Jamieson, Fausset and Brown on John 13:33-35

33-35. Little children--From the height of His own glory He now descends, with sweet pity, to His "little children," all now His own. This term of endearment, nowhere else used in the Gospels, and once only employed by Paul (Ga 4:19), is appropriated by the beloved disciple himself, who no fewer than seven times employs it in his first Epistle.

Ye shall seek me--feel the want of Me.

as I said to the Jews--(Joh 7:34; 8:21). But oh in what a different sense!