Willam Gouge in his commentary on Hebrews (if you are ever going to teach or preach on the book of Hebrews, you must consult Gouge’s commentary. He raises every issue — at the very least, he misses very few — which you could or should consider for a text), considers the text of Hebrews 1:3, “he sat down”. Gouge notes that Acts 7:55states that Stephen saw Christ stand.
Gouge sets out a three part test to determine whether an actual conflict or contradiction exists between texts. Many supposed conflicts could be resolved if readers thought more carefully about what was said. Gouge’s test will help distinguish between a conflict which arises from careless reading and an actual conflict.
Since this was the 17th Century, Gouge expected his readers to have a substantial, classical education — hence the use of Greek and Latin to make his point clear. If you don’t know either, don’t worry. The English phrase at the beginning of each sentence is merely repeated in Greek and Latin:
There are three limitations wherein different acts cannot be attributed to the same thing.
1. In the same part, κατὰ τὸ ἀυτὸ, secundum idem. In the very same part a man cannot be sore and sound.
2. In the same respect, πρὸς τὸ ἀυτὸ, ad idem, a man cannot be alive and dead together in the same respect, but in different respects one may be so; for ‘she that liveth in pleasure is dead while she liveth,’ 1 Tim. 5:6.
3. At the same time, ἐν τῶ ἄυτω χρόνω, eodem tempore, one cannot sit and stand together at the same time; at several times he may
Applying this test to Hebrews 1:3 and Acts 7:55, Gouge shows there is no contradiction:
Again, to take this phrase metaphorically (as it is here to be taken), Christ may be said to sit, to shew his authority (as before); and to stand, to shew his readiness to hear and help.1 In this respect did Christ most fitly present himself standing to Stephen, Acts 7:55.