حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا عِيسَى بْنُ يُونُسَ، حَدَّثَنَا الأَعْمَشُ، عَنْ أَبِي صَالِحٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم مِثْلَهُ ‏.‏ قَالَ أَبُو صَالِحٍ فَقُلْتُ لاِبْنِ عُمَرَ فَأَرْبَعَةٌ قَالَ لاَ يَضُرُّكَ ‏.‏

A similar tradition has been transmitted by Ibn `Umar through a different chain of narrators. This version has: Abu Salih said: I asked Ibn `Umar: If they are four? He replied: Then it does not harm you. Translation Not Available

Book Ref: Sunan Abi Dawud Book 43 Hadith 4852
Web Ref:  Sunan Abi Dawud Book 42 Hadith 4834