'Dumb' in the Bible

Let the lying lips be dumb, Which speak against the righteous insolently, With pride and contempt.

But I, as a deaf man, hear not; And I am as a dumb man that openeth not his mouth.

I was dumb with silence, I held my peace, even from good; And my sorrow was stirred.

I was dumb, I opened not my mouth; Because thou didst it.