The word(s) "dumb" appears 6 time(s) in 6 verse(s) in Quran in Saheeh International translation.

(1) Deaf, dumb and blind - so they will not return [to the right path].

(2) The example of those who disbelieve is like that of one who shouts at what hears nothing but calls and cries cattle or sheep - deaf, dumb and blind, so they do not understand.

(3) But those who deny Our verses are deaf and dumb within darknesses. Whomever Allah wills - He leaves astray; and whomever He wills - He puts him on a straight path.

(4) Indeed, the worst of living creatures in the sight of Allah are the deaf and dumb who do not use reason.

(5) And Allah presents an example of two men, one of them dumb and unable to do a thing, while he is a burden to his guardian. Wherever he directs him, he brings no good. Is he equal to one who commands justice, while he is on a straight path?

(6) And whoever Allah guides - he is the [rightly] guided; and whoever He sends astray - you will never find for them protectors besides Him, and We will gather them on the Day of Resurrection [fallen] on their faces - blind, dumb and deaf. Their refuge is Hell; every time it subsides We increase them in blazing fire.