The word(s) "mouth" appears 15 time(s) in 15 verse(s) in Quran in Mohsin Khan translation.

(11) "And loose the knot (the defect) from my tongue, (i.e. remove the incorrectness from my speech) [That occurred as a result of a brand of fire which Musa (Moses) put in his mouth when he was an infant]. (Tafsir At-Tabari).

(12) When you were propagating it with your tongues, and uttering with your mouths that whereof you had no knowledge, you counted it a little thing, while with Allah it was very great.

(13) Allah has not made for any man two hearts inside his body. Neither has He made your wives whom you declare to be like your mothers' backs, your real mothers. [az-Zihar is the saying of a husband to his wife, "You are to me like the back of my mother" i.e. You are unlawful for me to approach], nor has He made your adopted sons your real sons. That is but your saying with your mouths. But Allah says the truth, and He guides to the (Right) Way.

(14) This Day, We shall seal up their mouths, and their hands will speak to Us, and their legs will bear witness to what they used to earn. (It is said that one's left thigh will be the first to bear the witness). [Tafsir At-Tabari,]

(15) They intend to put out the Light of Allah (i.e. the Religion of Islam, this Qur'an, and the Prophet Muhammad صلى الله عليه وسلم) with their mouths. But Allah will bring His Light to perfection even though the disbelievers hate (it).