Mishkat al-Masabih 11 Business Transactions كتاب البيوع 109

وَعَنِ ابْنِ عُمَرَ قَالَ: كُنْتُ أَبِيعُ الْإِبِلَ بالنقيع بِالدَّنَانِيرِ فآخذ مَكَانهَا الدارهم وأبيع بِالدَّرَاهِمِ فَآخُذُ مَكَانَهَا الدَّنَانِيرَ فَأَتَيْتُ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَذَكَرْتُ ذَلِكَ لَهُ فَقَالَ: «لَا بَأْسَ أَنْ تَأْخُذَهَا بِسِعْرِ يَوْمِهَا مَا لَمْ تَفْتَرِقَا وَبَيْنَكُمَا شَيْءٌ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُد وَالنَّسَائِيّ والدارمي

Ibn ‘Umar said he used to sell camels at an-Naqi‘for dinars and take dirhams for them, and sell for dirhams and take dinars for them. He went to the Prophet and mentioned that to him, and he replied, “There is no harm in taking them at the current rate so long as you do not separate leaving something still to be settled.” Tirmidhi, Abu Dawud, Nasa’i and Darimi transmitted it.