John Gill Commentary Psalms 38:13

"But I, as a deaf man, hear not; And I am as a dumb man that openeth not his mouth." — Psalms 38:13 (ASV)

But I, as a deaf [man], heard not
He acted the part of a deaf man, and made as if he did not hear the mischievous things his enemies spoke; as Saul, when the sons of Belial spoke against him and despised him, (1 Samuel 10:27) ; and as our Lord when his enemies accused him, (Matthew 27:12–14) ;

and [I was] as a dumb man, [that] openeth not his mouth ;
made no reply to what they said, and did not render railing for railing; in which Christ was the antitype of him, (Isaiah 53:7) (1 Peter 2:23) (3:9) .