Dalil

Quran An-Nisa 4:2

وَءَاتُواْ ٱلۡيَتَٰمَىٰٓ أَمۡوَٰلَهُمۡۖ وَلَا تَتَبَدَّلُواْ ٱلۡخَبِيثَ بِٱلطَّيِّبِۖ وَلَا تَأۡكُلُوٓاْ أَمۡوَٰلَهُمۡ إِلَىٰٓ أَمۡوَٰلِكُمۡۚ إِنَّهُۥ كَانَ حُوبٗا كَبِيرٗا

Translation

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.