John Gill Commentary Psalms 38:14

"Yea, I am as a man that heareth not, And in whose mouth are no reproofs." — Psalms 38:14 (ASV)

Thus I was as a man that hears not
Any thing that is said to him; he took no more notice of it than if he had never heard it; but bore all the railings and calumnies of men with calmness and patience;

and in whose mouth no reproofs ;
as if he had nothing to say for himself, in vindication of his character, and to the refutation of his enemies; as if he had no arguments to make use of, for the conviction and reproof of his adversaries.