Merits of the Helpers in Madinah (Ansaar)
حَدَّثَنِي الْحَسَنُ بْنُ عُمَرَ بْنِ شَقِيقٍ، حَدَّثَنَا مُعْتَمِرٌ، قَالَ أَبِي وَحَدَّثَنَا أَبُو عُثْمَانَ، عَنْ سَلْمَانَ الْفَارِسِيِّ، أَنَّهُ تَدَاوَلَهُ بِضْعَةَ عَشَرَ مِنْ رَبٍّ إِلَى رَبٍّ.Narrated Salman Al-Farisi:That he was sold (as a slave) by one master to another for more than ten times (i.e. between 13 and)
From Sahih al-Bukhari, whose reports the scholars accept as authentic.