﴿ وَلَا تَقْرَبُوا۟ مَالَ ٱلْيَتِيمِ إِلَّا بِٱلَّتِى هِىَ أَحْسَنُ حَتَّىٰ يَبْلُغَ أَشُدَّهُۥ ۚ وَأَوْفُوا۟ بِٱلْعَهْدِ ۖ إِنَّ ٱلْعَهْدَ كَانَ مَسْـُٔولًۭا ﴾

“And do not touch the substance of an orphan, save to improve it, before he comes of age. And be true to every promise - for, verily, [on Judgment Day] you will be called to account for every promise which you have made!”

Please check ayah 17:35 for complete tafsir.