حَدَّثَنَا هَارُونُ بْنُ مُعَاوِيَةَ ، عَنْ أَبِي سُفْيَانَ ، عَنْ مَعْمَرٍ ، عَنْ قَتَادَةَ ، قَالَ :" إِذَا ابْتَاعَ الْمُكَاتَبَانِ أَحَدُهُمَا الْآخَرَ : هَذَا هَذَا مِنْ سَيِّدِهِ، وَهَذَا هَذَا مِنْ سَيِّدِهِ، فَالْبَيْعُ لِلْأَوَّلِ.
وَيَقُولُ أَهْلُ الْمَدِينَةِ : الْوَلَاءُ لِسَيِّدِ الْبَائِعِ، وَيَقُولُونَ : إِنَّمَا ابْتَاعَ هَذَا مَا عَلَى الْمُكَاتَبِ، فَالْوَلَاءُ لِلسَّيِّدِ

Harun bin Muawiyah told us, on the authority of Abu Sufyan, on the authority of Muammar, on the authority of Qatada, who said: “If two agents buy one another: This one is from his master, and this one is from his master, so the sale is to the first.
The people of the city say: Loyalty is to the master of the seller, and they say: This man bought what was on the counter, so loyalty is to the master.