The word(s) "faithfully" appears 2 time(s) in 2 verse(s) in Quran in Saheeh International translation.

(1) And if you are on a journey and cannot find a scribe, then a security deposit [should be] taken. And if one of you entrusts another, then let him who is entrusted discharge his trust [faithfully] and let him fear Allah, his Lord. And do not conceal testimony, for whoever conceals it - his heart is indeed sinful, and Allah is Knowing of what you do.

(2) It is not [attributable] to any prophet that he would act unfaithfully [in regard to war booty]. And whoever betrays, [taking unlawfully], will come with what he took on the Day of Resurrection. Then will every soul be [fully] compensated for what it earned, and they will not be wronged.