Abdullah b. Umar (Allah be pleased with them) reported Allah's Massenger (ﷺ) as saying: He who buys a tree after it has been fecundated, its fruit belongs to one who sells it except when the provision has been laid down by the buyer (that it will belong to him), and he who buys a slave, his property belongs to one who sells him except when a provision has been laid down by the buyer (that it will be transferred to him with the slave).
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، وَمُحَمَّدُ بْنُ رُمْحٍ، قَالاَ أَخْبَرَنَا اللَّيْثُ، ح وَحَدَّثَنَا قُتَيْبَةُ بْنُ، سَعِيدٍ حَدَّثَنَا لَيْثٌ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ بْنِ عُمَرَ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَنِ ابْتَاعَ نَخْلاً بَعْدَ أَنْ تُؤَبَّرَ فَثَمَرَتُهَا لِلَّذِي بَاعَهَا إِلاَّ أَنْ يَشْتَرِطَ الْمُبْتَاعُ وَمَنِ ابْتَاعَ عَبْدًا فَمَالُهُ لِلَّذِي بَاعَهُ إِلاَّ أَنْ يَشْتَرِطَ الْمُبْتَاعُ " .
sunnah.com