The Women - 4:2
Give to the orphans their property. Do not exchange the clean for the unclean. And do not eat their property with your own. That would be a great injustice.
About the property of orphans:
The Women/4:6
Test the orphans when they reach the age of marriage. If you see maturity in them, give them their property. Do not eat their wealth in extravagance and haste, lest they grow up. Let the rich give up (the wages of his efforts to protect the property). Let the poor spend an appropriate amount. Return their property to them in the presence of witnesses. Allah is sufficient as the Reckoner.
The Women/4:10
Those who eat the property of orphans unjustly will fill their bellies with fire and will end up in Hell.
The Cattle/6:152
Do not approach the property of orphans until they reach the age of maturity. Measure and weigh accurately. We do not burden a person with what he is not able. When you speak, be truthful even against your relatives. Keep your promise to Allah. These are His admonitions to you that you may take a lesson.
The Night Journey/17:34
Do not touch the property of orphans until they reach the age of maturity, except for their benefit. And fulfill your promises. For you will be held accountable for what you have promised.
The Cow/2:220
"About this world and the Hereafter And they ask you about orphans: Say, "It is the greatest good if you bring them up as righteous people. If you add their property to your property, they will become members of your family."Allah knows how to distinguish the corrupt from the righteous. Had Allah willed, He could have made you hardship. Allah is Mighty, Wise."