ENOfficial
‘Abdallah b. ‘Umar reported God's Messenger as saying, “If anyone buys a slave and makes no stipulation about his property, he gets none of it.” Darimi transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنِ اشْتَرَى عَبْدًا فَلَمْ يَشْتَرِطْ مَاله فَلَا شَيْء لَهُ» . رَوَاهُ الدَّارمِيّ
sunnah.com