9- أَحْمَدُ بْنُ مُحَمَّدٍ عَنِ ابْنِ مَحْبُوبٍ عَنْ رِفَاعَةَ النَّخَّاسِ قَالَ سَأَلْتُ أَبَا الْحَسَنِ مُوسَى (عَلَيْهِ السَّلام) قُلْتُ لَهُ أَيَصْلُحُ لِي أَنْ أَشْتَرِيَ مِنَ الْقَوْمِ الْجَارِيَةَ الآبِقَةَ وَأُعْطِيَهُمُ الثَّمَنَ وَأَطْلُبَهَا أَنَا قَالَ لا يَصْلُحُ شِرَاؤُهَا إِلا أَنْ تَشْتَرِيَ مِنْهُمْ مَعَهَا شَيْئاً ثَوْباً أَوْ مَتَاعاً فَتَقُولَ لَهُمْ أَشْتَرِي مِنْكُمْ جَارِيَتَكُمْ فُلانَةَ وَهَذَا الْمَتَاعَ بِكَذَا وَكَذَا دِرْهَماً فَإِنَّ ذَلِكَ جَائِزٌ.
9. Ahmad ibn Muhammad has narrated from ibn Mahbub from Rifa’ah al-Nakhkhas who has said the following: “I once asked abu al-Hassan, Musa 
, if my buying a runaway slave-girl from a people and paying them the price but myself search to find her, is valid. He (the Imam) said, ‘It is not valid unless you buy from them a certain other item, like cloths or so and say to them, “I buy your so slave- girl and this item of goods for so and so amount of dirham.” This is permissible.’”
