'Dumb' in the Bible

Then leap as a hart doth the lame, And sing doth the tongue of the dumb, For broken up in a wilderness have been waters, And streams in a desert.

It hath been exacted, and he hath answered, And he openeth not his mouth, As a lamb to the slaughter he is brought, And as a sheep before its shearers is dumb, And he openeth not his mouth.

Blind are his watchmen -- all of them, They have not known, All of them are dumb dogs, they are not able to bark, Dozing, lying down, loving to slumber.