ENOfficial
‘Abdallah b. ‘Abbas said that he heard God’s messenger say, “When a skin is tanned it is pure." Muslim transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسلم يَقُول: «إِذَا دُبِغَ الْإِهَابُ فَقَدْ طَهُرَ» . رَوَاهُ مُسْلِمٌ
sunnah.com