Surely Allah is not ashamed to set forth any parable-- (that of) a gnat or any thing above that; then as for those who believe, they know that it is the truth from their Lord, and as for those who disbelieve, they say: What is it that Allah means by this parable: He causes many to err by it and many He leads aright by it! but He does not cause to err by it (any) except the transgressors,

And if you are upon a journey and you do not find a scribe, then (there may be) a security taken into possession; but if one of you trusts another, then he who is trusted should deliver his trust, and let him be careful (of his duty to) Allah, his Lord; and do not conceal testimony, and whoever conceals it, his heart is surely sinful; and Allah knows what you do.