Saheeh International

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 Allāh, his Lord. And do not conceal testimony, for whoever conceals it - his heart is indeed sinful, and Allāh is Knowing of what you do.