To orphans restore their property (When they reach their age), nor substitute (your) worthless things for (their) good ones; and devour not their substance (by mixing it up) with your own. For this is indeed a great sin. (4:2)

If ye fear that ye shall not be able to deal justly with the orphans, Marry women of your choice, Two or three or four; but if ye fear that ye shall not be able to deal justly (with them), then only one, or (a captive) that your right hands possess, that will be more suitable, to prevent you from doing injustice. (4:3)

Those who unjustly eat up the property of orphans, eat up a Fire into their own bodies: They will soon be enduring a Blazing Fire! (4:10)

Come not nigh to the orphan's property except to improve it, until he attains the age of full strength; and fulfil (every) engagement, for (every) engagement will be enquired into (on the Day of Reckoning). (17:34)