In this verse (as is indicated by the word for
) we are given the reason as to why prophecies, tongues, and knowledge will pass away: these gifts are limited and incomplete.
Here, and again in 1 Corinthians 13:12, Paul uses the plural pronoun we.
He may have in mind himself and his fellow apostles and prophets, or he may be referring more broadly to all believers.
Paul chooses not to mention tongues again probably for the sake of rhythm and perhaps also because speaking in tongues is included in the term prophecy.
9 For we know in part and we prophesy in part,