The word(s) "mouth" appears 13 time(s) in 13 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) O you who believe! do not take for intimate friends from among others than your own people; they do not fall short of inflicting loss upon you; they love what distresses you; vehement hatred has already appeared from out of their mouths, and what their breasts conceal is greater still; indeed, We have made the communications clear to you, if you will understand.

(2) And that He might know the hypocrites; and it was said to them: Come, fight in Allah's way, or defend yourselves. They said: If we knew fighting, we would certainly have followed you. They were on that day much nearer to unbelief than to belief. They say with their mouths what is not in their hearts, and Allah best knows what they conceal.

(3) O Apostle! let not those grieve you who strive together in hastening to unbelief from among those who say with their mouths: We believe, and their hearts do not believe, and from among those who are Jews; they are listeners for the sake of a lie, listeners for another people who have not come to you; they alter the words from their places, saying: If you are given this, take it, and if you are not given this, be cautious; and as for him whose temptation Allah desires, you cannot control anything for him with Allah. Those are they for whom Allah does not desire that He should purify their hearts; they shall have disgrace in this world, and they shall have a grievous chastisement in the hereafter.

(4) How (can it be)! while if they prevail against you, they would not pay regard in your case to ties of relationship, nor those of covenant; they please you with their mouths while their hearts do not consent; and most of them are transgressors.

(5) And the Jews say: Uzair is the son of Allah; and the Christians say: The Messiah is the son of Allah; these are the words of their mouths; they imitate the saying of those who disbelieved before; may Allah destroy them; how they are turned away!

(6) They desire to put out the light of Allah with their mouths, and Allah will not consent save to perfect His light, though the unbelievers are averse.

(7) To Him is due the true prayer; and those whom they pray to besides Allah give them no answer, but (they are) like one who stretches forth his two hands towards water that it may reach his mouth, but it will not reach it; and the prayer of the unbelievers is only in error.

(8) Has not the account reached you of those before you, of the people of Nuh and Ad and Samood, and those after them? None knows them but Allah. Their apostles come to them with clear arguments, but they thrust their hands into their mouths and said: Surely we deny that with which you are sent, and most surely we are in serious doubt as to that to which you invite us.

(9) They have no knowledge of it, nor had their fathers; a grievous word it is that comes out of their mouths; they speak nothing but a lie.

(10) When you received it with your tongues and spoke with your mouths what you had no knowledge of, and you deemed it an easy matter while with Allah it was grievous.