The word(s) "mouth" appears 13 time(s) in 13 verse(s) in Quran in Saheeh International translation.

(1) O you who have believed, do not take as intimates those other than yourselves, for they will not spare you [any] ruin. They wish you would have hardship. Hatred has already appeared from their mouths, and what their breasts conceal is greater. We have certainly made clear to you the signs, if you will use reason.

(2) And that He might make evident those who are hypocrites. For it was said to them, "Come, fight in the way of Allah or [at least] defend." They said, "If we had known [there would be] fighting, we would have followed you." They were nearer to disbelief that day than to faith, saying with their mouths what was not in their hearts. And Allah is most Knowing of what they conceal -

(3) O Messenger, let them not grieve you who hasten into disbelief of those who say, "We believe" with their mouths, but their hearts believe not, and from among the Jews. [They are] avid listeners to falsehood, listening to another people who have not come to you. They distort words beyond their [proper] usages, saying "If you are given this, take it; but if you are not given it, then beware." But he for whom Allah intends fitnah - never will you possess [power to do] for him a thing against Allah. Those are the ones for whom Allah does not intend to purify their hearts. For them in this world is disgrace, and for them in the Hereafter is a great punishment.

(4) How [can there be a treaty] while, if they gain dominance over you, they do not observe concerning you any pact of kinship or covenant of protection? They satisfy you with their mouths, but their hearts refuse [compliance], and most of them are defiantly disobedient.

(5) The Jews say, "Ezra is the son of Allah "; and the Christians say, "The Messiah is the son of Allah." That is their statement from their mouths; they imitate the saying of those who disbelieved [before them]. May Allah destroy them; how are they deluded?

(6) They want to extinguish the light of Allah with their mouths, but Allah refuses except to perfect His light, although the disbelievers dislike it.

(7) To Him [alone] is the supplication of truth. And those they call upon besides Him do not respond to them with a thing, except as one who stretches his hands toward water [from afar, calling it] to reach his mouth, but it will not reach it [thus]. And the supplication of the disbelievers is not but in error [i.e. futility].

(8) Has there not reached you the news of those before you - the people of Noah and 'Aad and Thamud and those after them? No one knows them but Allah. Their messengers brought them clear proofs, but they returned their hands to their mouths and said, "Indeed, we disbelieve in that with which you have been sent, and indeed we are, about that to which you invite us, in disquieting doubt."

(9) They have no knowledge of it, nor had their fathers. Grave is the word that comes out of their mouths; they speak not except a lie.

(10) When you received it with your tongues and said with your mouths that of which you had no knowledge and thought it was insignificant while it was, in the sight of Allah, tremendous.