Hadithcore
Hadith #513620

Yahya related to me from Malik that he had heard that a man said to another, "Buy this camel for me immediately so that I can buy him from you on credit." Abdullah ibn Umar was asked about that and he disapproved of it and forbade it.

وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَجُلاً، قَالَ لِرَجُلٍ ابْتَعْ لِي هَذَا الْبَعِيرَ بِنَقْدٍ حَتَّى أَبْتَاعَهُ مِنْكَ إِلَى أَجَلٍ فَسُئِلَ عَنْ ذَلِكَ عَبْدُ اللَّهِ بْنُ عُمَرَ فَكَرِهَهُ وَنَهَى عَنْهُ ‏.‏

References1 variant
Arabic/English book reference
Book 31, Hadith 73