An-Nisa 4:2

Waatoo alyatama amwalahumwala tatabaddaloo alkhabeetha bittayyibiwala ta/kuloo amwalahum ila amwalikuminnahu kana hooban kabeera

And give to the orphans their properties and do not substitute the defective [of your own] for the good [of theirs]. And do not consume their properties into your own. Indeed, that is ever a great sin.

Give the orphans their property, and do not substitute what is bad for what is good, and do not eat up their property along with your own. It is, surely, a great sin.