Various commentators:

              4. Man shall not live by bread alone. He quotes the statement, that men do not live by bread alone, but by the secret blessing of God. Hence we conclude, that Satan made a direct attack on the faith of Christ, in the hope that, after destroying his faith, he would drive Christ to unlawful and wicked methods of procuring food. And certainly he presses us very hard, when he attempts to make us distrust God, and consult our own advantage in a way not authorized by his word. The meaning of the words, therefore, is: “When you see that you are forsaken by God, you are driven by necessity to attend to yourself. Provide then for yourself the food, with which God does not supply you.” Now, though3 he holds out the divine power of Christ to turn the stones into loaves, yet the single object which he has in view, is to persuade Christ to depart from the word of God, and to follow the dictates of infidelity.

Christ’s reply, therefore, is appropriate: “Man shall not live by bread alone. You advise me to contrive some remedy, for obtaining relief in a different manner from what God permits. This would be to distrust God; and I have no reason to expect that he will support me in a different manner from what he has promised in his word. You, Satan, represent his favour as confined to bread: but Himself declares, that, though every kind of food were wanting, his blessing alone is sufficient for our nourishment.” Such was the kind of temptation which Satan employed, the same kind with which he assails us daily. The Son of God did not choose to undertake any contest of an unusual description, but to sustain assaults in common with us, that we might be furnished with the same armour, and might entertain no doubt as to achieving the victory.

John Calvin and William Pringle, Commentary on a Harmony of the Evangelists Matthew, Mark, and Luke (Bellingham, WA: Logos Bible Software, 2010), Mt 4:4.

Man does not live on bread alone. This, as well as the other two temptations, was messianic in nature in that Jesus understood the messianic role as requiring that he too must humble himself and trust himself to God (cf. Phil 2:7–8). Israel in the wilderness needed to trust God for their sustenance; so must God’s Son (Deut 8:1–3).

Robert H. Stein, vol. 24, Luke, The New American Commentary (Nashville: Broadman & Holman Publishers, 1992), 146.

Ver. 3.—The tempter (1 Thess. 3:5 only; cf. 2 Cor. 11:3). Came; came up to him (προσελθών). The word expresses local nearness, and suggests, though we cannot affirm it as certain, that he appeared visibly. The thought of physical nearness is continued in “taketh him” (vers. 5, 8), and “the devil leaveth him” and “angels came near” (ver. 11; cf. ver. 5, note). On the other hand, such expressions may be parabolic, and intended to express the closeness of the spiritual combat. To him; not after “came,” but after “said” (Revised Version, with manuscripts). If thou be; art (Revised Version) (εἰ … εἰ)—the “if” of assumption (cf. Col. 3:1). The devil does not attempt to throw doubt on the truth of the utterance in ch. 3:17. His words rather mean, “Thou knowest what was said, thou hast been gradually realizing that assurance of Sonship; use, then, that privilege which thou undoubtedly hast” (comp. ch. 27:40, where, in mockery, the same truth is assumed). Wetstein, following Origen and pseudo-Ignatius, ‘Philipp.,’ § 9, says that the tempter did not know, or at least doubted, whether Jesus was really God, for otherwise he would never have tempted him. This is, surely, to miss the meaning of the temptation for our Lord himself; for he was tempted as Man. Satan might well have known that he was God incarnate, and yet not have known whether as Man he might not yield. Weiss (‘Life,’ i. 343) mistakenly thinks that the object of this first temptation was to insinuate doubt in the mind of Jesus as to his Messiahship. “Command that these stones become bread, and if thou canst not do so, then thou art not the Son of God.” Command that; εἰπὸν (cf. Westcott and Hort, ii. App., p. 164) ἵνα (cf. ch. 20:21, and Winer, § 44:8). These stones, i.e. lying about. Farrar (on Luke 4:3; and especially in ‘Life of Christ,’ illustrated edit., pp. 99, 100) suggests that there is a special reference to the “loaf-shaped fossils,” septaria, which are found in Palestine—as, indeed, in most other countries. But though these “flattened nodules of calcareous clay, ironstone, or other matter” (Page, ‘Handbook of Geolog. Terms,’ etc., 1859, p. 327) often assume fantastic shapes, perhaps even distantly resembling either an English loaf or a flat Jewish cake (vide infra), it seems quite unnecessary to see any allusion to them here. (For the comparison of bread and a stone, cf. ch. 7:9.) Be made; Revised Version, become; rightly, because there is no thought of the process of manufacture in γένωνται. Bread; Revised Version margin, “Greek, loaves” (ἄρτοι). “The Israelites made bread in the form of an oblong or round cake, as thick as one’s thumb, and as large as a plate or platter: hence it was not cut, but [e.g. ch. 14:19] broken” (Thayer). In Luke the devil points to one stone only, and tempts him to bid it become a loaf.

Ver. 4.—It is written. Our Lord’s three quotations are from Deut. 8:3; 6:16, 13. Some portion of Deuteronomy (ch. 6:4–9; 11:13–21, because included in the Sh’ma) was the first part of Scripture taught a Jewish child. Possibly, though there is no evidence upon the subject, the neighbouring portions were often added. If they had been in our Lord’s case, such a recurrence of them to his mind in his present state of exhaustion is in complete accord with psychological probability. Man … God (Deut. 8:3, LXX). As we could not accept Weiss’s interpretation of the object of the devil’s temptation, so neither can we accept his interpretation of our Lord’s reply, that it is equivalent to “Not by means either natural or supernatural, is man’s life really sustained, but by exact obedience to God’s command.” Our Lord quotes the passage in its primary meaning, which was fully applicable to the present occasion. It is equivalent to “Man lives, not necessarily by natural means, but by even supernatural means, if God so wishes.” “The creative word, the ῤῆμα Θεοῦ, which alone imparts to the bread its sustaining power, can sustain, even as he is confident that in the present need it will sustain, apart from the bread” (Trench, ‘Studies,’ p. 35). The words of Deuteronomy are paraphrased in Wisd. 16:26, where the author, in a thoroughly Jewish exposition, enumerates the lessons taught by the giving of the manna. “It was altered … that thy children, O Lord, whom thou lovest, might know that it is not the growing of fruits that nourisheth man; but that it is thy Word, which preserveth them that put their trust in thee.” By every word. Ἐπί (Textus Receptus; Westcott and Hort) is doubtless right. The alteration to ἐν (Lachmann, Tregelles) is probably due to a tendency towards the simple expression of means, but perhaps to the feeling that life, especially spiritual life, is maintained rather in a sphere than on a basis (cf. Rom. 10:5; Gal. 3:12).

St. Matthew Vol. I, ed. H. D. M. Spence-Jones, The Pulpit Commentary (London; New York: Funk & Wagnalls Company, 1909), 104.

  … attention should not be on bread alone. When the Israelites were hungry in the wilderness and pined for the bread of Egypt (Exod 16:3), God provided manna to nourish them (Deut 8:3). There is no need to leave off attending to God to seek for oneself. Rather, one should seek God’s kingdom (Luke 12:31 [Mt. 12:31; 6:33]). The desire for bread should not determine the Son’s use of the possibilities and privileges that are his.37

While the possibility of having stones become bread suggests for Jesus a distinctive class of sonship, the answer operates in more general terms of human life before God. The temptation has a particular accentuation based on the distinctive identity of Jesus, but its fundamental shape is not different from temptation which faces other ‘sons of God’.38 Though, following the Hebrew dbr, ῥῆμα can have a more general sense (‘thing/matter’), elsewhere in Matthew it means ‘word’. So it is likely that Matthew thinks here of listening to God as that which is life-sustaining.

John Nolland, The Gospel of Matthew: A Commentary on the Greek Text, New International Greek Testament Commentary (Grand Rapids, MI; Carlisle: W.B. Eerdmans; Paternoster Press, 2005).

Tell this stone to become bread. Was this temptation a challenge to provide a sign (such as when God gave manna in the wilderness) in order for Jesus to gain a following? This is unlikely since no audience was present and the miracle was not to provide manna (loaves of bread, plural) for the people but a single loaf for Jesus’ own hunger. Or was this a temptation to cause Jesus to doubt that he really is the Son of God? This also is unlikely since Jesus’ answer did not deal with such a thought. More likely Jesus was tempted to use his power as God’s Son for his own ends. Jesus clearly rejected such a view of his messianic role since it would indicate a lack of trust on his part in the provision and care of his Heavenly Father. He also had to trust and pray, “Give us each day our daily bread” (11:3) and seek first the kingdom of God (12:31), just as he would soon teach his disciples. Later Luke recorded a miracle of Jesus’ multiplying bread (9:10–17), but that was to satisfy the needs of others. Jesus would not, however, use his messianic anointing to satisfy his own needs but rather would submit himself to his Father.

4:4 Jesus answered, “It is written.” Throughout his temptations Jesus found his answers in the Scriptures. He was armed with the “sword of the Spirit” (Eph 6:17) for his battle with the devil. See comments on 2:23.

1. The saying has been interpreted as a temptation to perform one of the signs expected in the messianic age in order to win the people over to his side: let Jesus repeat the miracle of the manna in the wilderness (Ex. 16; Manson, Sayings, 43f.). It can then be argued that this temptation is to be connected with the feeding of the five thousand (Jn. 6:31f.) and reflects the temptation to become king experienced by Jesus on that occasion (R. E. Brown, ‘Incidents that are units in the Synoptic Gospels but dispersed in St. John’, CBQ 23, 1961, 143–160, especially 152–155). But this view is certainly wrong. There are no onlookers (B. Gerhardsson*, 32), and the suggestion of producing one loaf is linked to Jesus’ own hunger. Nothing suggests an allusion to the manna. Only in Ps.-Clem. Hom. 2:32 is the miracle turned into a messianic wonder performed by Simon Magus (Schürmann, I, 209; Schulz, 185 n. 84). 2. A second possibility is that the devil is attempting to cast doubt on Jesus’ possession of the miraculous powers which would confirm for him the reality of his divine sonship (Ellis, 94). Jesus’ answer, however, is not concerned with this point. 3. The third view remains the most likely, namely that Jesus is being tempted to use his power as Son of God for his own ends instead of being obedient to the Father (Creed, 62; Schürmann, I, 209). It is suggested that Sonship can be expressed in independent authority rather than in filial obedience. Behind the temptation lies the desire to turn Jesus aside from the fulfilment of his messianic task by striking at his relationship to the Father. That this is the correct view of the temptation is confirmed by Jesus’ reply.

I. Howard Marshall, The Gospel of Luke: A Commentary on the Greek Text, New International Greek Testament Commentary (Exeter: Paternoster Press, 1978), 170-71.

Ver. 3.—And the devil said unto him, If thou be the Son of God, command this stone that it be made bread. It has been quaintly said of the tempter “that he had sped so successfully to his own mind by a temptation about a matter of eating with the first Adam, that he practised the old manner of his trading with the second.” These diabolical promptings have been spoken of already in this Commentary as “typical.” They represent, indeed, some of the principal temptations to which different classes of men and women in all ages are subject; the hard task of bread-winning, after all, suggests very many of the evil thoughts and imaginings to which men are subject, though, perhaps, they suspect it not. Weakened and exbausted by long abstinence from food, the temptation to supply his wants by this easy means at once was great. Still, had he consented to the tempter’s suggestion, Jesus was aware that he would have broken the conditions of that human existence to which, in his deep love for us fallen beings, he had voluntarily consented and submitted himself. Should he, then, use his miraculous power for his own advantage? Then, remembering his own late experience, the long fast from all human food, and yet life enduring through it all; calling to mind the miraculous supply of manna in the old desert days, the preservation of Elijah’s life through a similar fast,—Jesus, all faint and weary, exclaims in reply, “Man shall not live by bread alone.”^[1]

…The Devil suggests that Sonship is a privilege to be exploited. Jesus is tempted to order his own affairs and provide for his own needs, rather than being nourished in filial dependence on God. The single “loaf” and “stone” of Luke’s account is a more appropriate response to hunger than Matthew’s “loaves” and “stones.”

4 Jesus’ reply is from the LXX text of Deut 8:3b (which follows the MT closely). Matthew has a longer quotation. The Lukan focus is on the negative: attention should not be on bread alone. When the Israelites were hungry in the wilderness and pined for the bread of Egypt (Exod 16:3), God provided manna to nourish them (Deut 8:3). There is no need to leave off attending to God to seek for oneself. Rather, one should seek God’s kingdom (Luke 12:31). The desire for bread should not determine the Son’s use of the possibilities and privileges that are his.

John Nolland, vol. 35A, Luke 1:1–9:20, Word Biblical Commentary (Dallas: Word, Incorporated, 2002), 179.