1 Corinthians 14:20 - Coke's Commentary on the Holy Bible

Be not children in understanding:— This is an admirable stroke of true oratory, adapted to humble their spirits, by representing those things in which they were most ready to pride themselves, as comparatively little. The word u957?ηπιαζετε refers to infants, and is not sufficiently expressed by the word children; for they are sometimes vain, and sometimes malicious too; the old Adam more or less discovers itself in them: it should rather be rendered, be little infants in malice,κακια, by which is to be understood all sorts of evil tempers of mind which are contrary to the gentleness of childhood; and in particular their emulation and strife about the exercise of their gifts in their assemblies. The word τελειοι signifies full-grown men; intimating, that it was a kind of puerility to emulate, and to quarrel with one another.