" أَيُّمَا رَجُلٍ أَعْمَرَ رَجُلاً عُمْرَى لَهُ وَلِعَقِبِهِ فَهِيَ لَهُ وَلِمَنْ يَرِثُهُ مِنْ عَقِبِهِ مَوْرُوثَةٌ "
It was narrated from Hisham bin 'Urwah, from his father, from 'Abdullah bin Az-Zubair, that the Messenger of Allah said: "Any man who gives a lifelong gift to another man, it belongs to him (the recipient) and to his descendants, and to those who inherit from him."