Jamieson, Fausset and Brown on 1 Corinthians 1:5

5. utterance--Alford from Menochius translates, "doctrine." Ye are rich in preachers or the preaching of the word, and rich in knowledge or apprehension of it: literally "(the) word (preached)." English Version (as in 2Co 8:7) is better: for Paul, purposing presently to dwell on the abuse of the two gifts on which the Corinthians most prided themselves, utterance (speech) and knowledge (1Co 1:20; 3:18; 4:19; 1Co 13:1-14:40), previously gains their goodwill by congratulating them on having those gifts.