Sahih al-Bukhari, Volume 3, Book 35, Hadith 447 (USC-MSA) ⓘ

Narrated Muhammad bin Al-Mujalid: `Abdullah bin Shaddad and Abu Burda sent me to `Abdullah bin Abi `Aufa and told me to ask `Abdullah whether the people in the lifetime of the Prophet used to pay in advance for wheat (to be delivered later). `Abdullah replied, "We used to pay in advance to the peasants of Sham for wheat, barley and olive oil of a known specified measure to be delivered in a specified period." I asked (him), "Was the price paid (in advance) to those who had the things to be delivered later?" `Abdullah bin `Aufa replied, "We did not use to ask them about that." Then they sent me to `Abdur Rahman bin Abza and I asked him. He replied, "The companions of the Prophet used to practice Salam in the lifetime of the Prophet; and we did not use to ask them whether they had standing crops or not."

حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا عَبْدُ الْوَاحِدِ، حَدَّثَنَا الشَّيْبَانِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ أَبِي الْمُجَالِدِ، قَالَ بَعَثَنِي عَبْدُ اللَّهِ بْنُ شَدَّادٍ وَأَبُو بُرْدَةَ إِلَى عَبْدِ اللَّهِ بْنِ أَبِي أَوْفَى ـ رضى الله عنهما ـ فَقَالاَ سَلْهُ هَلْ كَانَ أَصْحَابُ النَّبِيِّ صلى الله عليه وسلم فِي عَهْدِ النَّبِيِّ صلى الله عليه وسلم يُسْلِفُونَ فِي الْحِنْطَةِ قَالَ عَبْدُ اللَّهِ كُنَّا نُسْلِفُ نَبِيطَ أَهْلِ الشَّأْمِ فِي الْحِنْطَةِ، وَالشَّعِيرِ، وَالزَّيْتِ، فِي كَيْلٍ مَعْلُومٍ، إِلَى أَجَلٍ مَعْلُومٍ‏.‏ قُلْتُ إِلَى مَنْ كَانَ أَصْلُهُ عِنْدَهُ قَالَ مَا كُنَّا نَسْأَلُهُمْ عَنْ ذَلِكَ‏.‏ ثُمَّ بَعَثَانِي إِلَى عَبْدِ الرَّحْمَنِ بْنِ أَبْزَى فَسَأَلْتُهُ فَقَالَ كَانَ أَصْحَابُ النَّبِيِّ صلى الله عليه وسلم يُسْلِفُونَ عَلَى عَهْدِ النَّبِيِّ صلى الله عليه وسلم وَلَمْ نَسْأَلْهُمْ أَلَهُمْ حَرْثٌ أَمْ لاَ