Sunan of Abu Dawood Book 24, Hadith 3507

حَدَّثَنَا هَارُونُ بْنُ عَبْدِ اللَّهِ، حَدَّثَنِي عَبْدُ الصَّمَدِ، حَدَّثَنَا هَمَّامٌ، عَنْ قَتَادَةَ، بِإِسْنَادِهِ وَمَعْنَاهُ زَادَ إِنْ وَجَدَ دَاءً فِي الثَّلاَثِ اللَّيَالِي رُدَّ بِغَيْرِ بَيِّنَةٍ وَإِنْ وَجَدَ دَاءً بَعْدَ الثَّلاَثِ كُلِّفَ الْبَيِّنَةَ أَنَّهُ اشْتَرَاهُ وَبِهِ هَذَا الدَّاءُ ‏.‏ قَالَ أَبُو دَاوُدَ هَذَا التَّفْسِيرُ مِنْ كَلاَمِ قَتَادَةَ ‏.‏

The tradition mentioned above has also been transmitted by Qatadah through a different chain of narrators to the same effect. This version adds:"If he finds defect (in the slave) within three days, he may return it without evidence; if he finds a defect after three days, he will be required to produce evidence that he (the slave) had the defect when he bought it." Abu Dawud said: This explanation is from the words of Qatadah