The word(s) "witness" appears 132 time(s) in 112 verse(s) in Quran in Abdullah Yusuf Ali translation.

(31) But if it gets known that these two were guilty of the sin (of perjury), let two others stand forth in their places,- nearest in kin from among those who claim a lawful right: let them swear by Allah: "We affirm that our witness is truer than that of those two, and that we have not trespassed (beyond the truth): if we did, behold! the wrong be upon us!"

(32) "And behold! I inspired the disciples to have faith in Me and Mine Messenger: they said, 'We have faith, and do thou bear witness that we bow to Allah as Muslims'".

(33) They said: "We only wish to eat thereof and satisfy our hearts, and to know that thou hast indeed told us the truth; and that we ourselves may be witnesses to the miracle."

(34) "Never said I to them aught except what Thou didst command me to say, to wit, 'worship Allah, my Lord and your Lord'; and I was a witness over them whilst I dwelt amongst them; when Thou didst take me up Thou wast the Watcher over them, and Thou art a witness to all things.

(35) Say: "What thing is most weighty in evidence?" Say: "Allah is witness between me and you; This Qur'an hath been revealed to me by inspiration, that I may warn you and all whom it reaches. Can ye possibly bear witness that besides Allah there is another Allah?" Say: "Nay! I cannot bear witness!" Say: "But in truth He is the one Allah, and I truly am innocent of (your blasphemy of) joining others with Him."

(36) "O ye assembly of Jinns and men! came there not unto you messengers from amongst you, setting forth unto you My signs, and warning you of the meeting of this Day of yours?" They will say: "We bear witness against ourselves." It was the life of this world that deceived them. So against themselves will they bear witness that they rejected Faith.

(37) Say: "Bring forward your witnesses to prove that Allah did forbid so and so." If they bring such witnesses, be not thou amongst them: Nor follow thou the vain desires of such as treat our signs as falsehoods, and such as believe not in the Hereafter: for they hold others as equal with their Guardian-Lord.

(38) Who is more unjust than one who invents a lie against Allah or rejects His Signs? For such, their portion appointed must reach them from the Book (of decrees): until, when our messengers (of death) arrive and take their souls, they say: "Where are the things that ye used to invoke besides Allah?" They will reply, "They have left us in the lurch," And they will bear witness against themselves, that they had rejected Allah.

(39) It is not for such as join gods with Allah, to visit or maintain the mosques of Allah while they witness against their own souls to infidelity. The works of such bear no fruit: In Fire shall they dwell.

(40) "Enough is Allah for a witness between us and you: we certainly knew nothing of your worship of us!"