The word(s) "testify" appears 5 time(s) in 4 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) If any of your women are guilty of lewdness, Take the evidence of four (Reliable) witnesses from amongst you against them; and if they testify, confine them to houses until death do claim them, or Allah ordain for them some (other) way.

(2) All who obey Allah and the messenger are in the company of those on whom is the Grace of Allah,- of the prophets (who teach), the sincere (lovers of Truth), the witnesses (who testify), and the Righteous (who do good): Ah! what a beautiful fellowship!

(3) When thy Lord drew forth from the Children of Adam - from their loins - their descendants, and made them testify concerning themselves, (saying): "Am I not your Lord (who cherishes and sustains you)?"- They said: "Yea! We do testify!" (This), lest ye should say on the Day of Judgment: "Of this we were never mindful":

(4) And those who believe in Allah and His messengers- they are the Sincere (lovers of Truth), and the witnesses (who testify), in the eyes of their Lord: They shall have their Reward and their Light. But those who reject Allah and deny Our Signs,- they are the Companions of Hell-Fire.