Mishkat al-Masabih 3968
Marwan and al-Miswar b. Makhrama told that when the deputation of Hawain came to God’s Messenger to accept Islam and asked him to return to them their property and their captives he stood up and said, “Choose one of the two, either the captives or the property.” When they replied that they chose their captives God’s Messenger stood up, and after extolling God in a fitting manner said, “To proceed:
Your brethren have come repentant and I have considered that I should return their captives to them, so let those of you who are willing to release the captives act accordingly, but those who wish to hold on to what they have till I give them some of the first booty God gives us may do so.” The people told God’s Messenger that they were willing to release the captives, and he said, “I cannot distinguish between those of you who have granted that and those who have not, so return that your headmen may tell me about you.” They did so, and after their headmen had spoken to them they came back to God’s Messenger and told him they were agreeable and had given permission. 

Bukhari transmitted it.
وَعَنْ مَرْوَانَ وَالْمِسْوَرِ بْنِ مَخْرَمَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَامَ حِينَ جَاءَهُ وَفد من هَوَازِنَ مُسْلِمِينَ فَسَأَلُوهُ أَنْ يَرُدَّ إِلَيْهِمْ أَمْوَالَهُمْ وَسَبْيَهُمْ فَقَالَ: 
" فَاخْتَارُوا إِحْدَى الطَّائِفَتَيْنِ: إِمَّا السَّبْيَ وَإِمَّا الْمَالَ ". قَالُوا: فَإِنَّا نَخْتَارُ سَبْيَنَا. فَقَامَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَأَثْنَى عَلَى اللَّهِ بِمَا هُوَ أَهْلُهُ ثُمَّ قَالَ: «أمَّا بعدُ فإِنَّ إِخْوانَكم قدْ جاؤوا تَائِبِينَ وَإِنِّي قَدْ رَأَيْتُ أَنْ أَرُدَّ إِلَيْهِمْ سَبْيَهُمْ فَمَنْ أَحَبَّ مِنْكُمْ أَنْ يُطَيِّبَ ذَلِكَ فَلْيَفْعَلْ وَمَنْ أَحَبَّ مِنْكُمْ أَنْ يَكُونَ عَلَى حظِّه حَتَّى نُعطِيَه إِيَّاهُ منْ أوَّلِ مَا يَفِيءُ اللَّهُ عَلَيْنَا فَلْيَفْعَلْ» فَقَالَ النَّاسُ: قَدْ طَيَّبْنَا ذَلِكَ يَا رَسُولَ اللَّهِ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّا لَا نَدْرِي مَنْ أَذِنَ مِنْكُمْ مِمَّنْ لَمْ يَأْذَنْ فَارْجِعُوا حَتَّى يَرْفَعَ إِلَيْنَا عُرَفَاؤُكُمْ أَمْرَكُمْ» . فَرَجَعَ النَّاسُ فَكَلَّمَهُمْ عُرَفَاؤُهُمْ ثُمَّ رَجَعُوا إِلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَأَخْبَرُوهُ أَنَّهُمْ قد طيَّبوا وأَذنوا. رَوَاهُ البُخَارِيّ