Sunan an-Nasa'i, Volume 4, Book 34, Hadith 3780 (DarusSalam) ⓘ

Yazid bin Abi Habib narrated from Ibn Shihab, from Abu Salamah, from Jabir, that the Messenger of Allah ruled concerning 'Umra -when a man gives a gift to another man, and his descendants, but stipulates that if something happens to you and your descendants, then it will belong to me and my descendants- "It belongs to the one to whom it was given, and to his descendants."

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ يَزِيدَ، قَالَ حَدَّثَنَا أَبِي قَالَ، حَدَّثَنَا سَعِيدٌ، قَالَ حَدَّثَنِي يَزِيدُ بْنُ أَبِي حَبِيبٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي سَلَمَةَ، عَنْ جَابِرٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَضَى بِالْعُمْرَى أَنْ يَهَبَ الرَّجُلُ لِلرَّجُلِ وَلِعَقِبِهِ الْهِبَةَ وَيَسْتَثْنِي إِنْ حَدَثَ بِكَ حَدَثٌ وَبِعَقِبِكَ فَهُوَ إِلَىَّ وَإِلَى عَقِبِي إِنَّهَا لِمَنْ أُعْطِيَهَا وَلِعَقِبِهِ ‏.‏