Tim Challies has an excellent article
HERE on how we should understand 1 Cor. 7:10-12, and Paul's use of "not I, but the Lord" followed by "I, not the Lord" in this section. Here is the upshot:
When I come across this text in books or blogs, I often find authors suggesting that in the first statement Paul is drawing upon a statement that is binding on all Christians while in the second he is either expressing humility or a kind of personal opinion. In either case, they highlight the full authority of the first statement and then diminish the authority of the second statement, saying something like, “Paul was humble enough to say that this was simply his understanding of the situation” or “In the second statement Paul was expressing his personal opinion.”
However, the contrast here is not between divine revelation and personal opinion. Rather, the contrast is between two different kinds of authority, each of which is from God and each of which is fully authoritative and fully binding.
Read the rest
HERE.