عَنْ رُوَيْفِعِ بْنِ ثَابِتٍ الْأَنْصَارِيِّ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَا رُوَيْفِعُ لَعَلَّ الْحَيَاةَ سَتَطُولُ بِكَ فَأَخْبِرِ النَّاسَ أَنَّهُ مَنْ عَقَدَ لِحْيَتَهُ أَوْ تَقَلَّدَ وَتَرًا أَوِ اسْتَنْجَى بِرَجِيعِ دَابَّةٍ أَوْ عَظْمٍ فَإِنَّ مُحَمَّدًا صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ مِنْهُ بَرِيءٌ (وَفِي لَفْظٍ) فَقَدْ بَرِيءَ مِمَّا أَنْزَلَ عَلَى مُحَمَّدٍ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ
Narrated from Sayyiduna Ruwaifi’ bin Thabit Ansari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: O Ruwaifi’! It is possible that your life will be prolonged, so inform the people that whoever ties a knot in his beard, or puts on a string necklace, or uses animal dung or bone for istinja (purification), then Muhammad (peace and blessings be upon him) is free from him. In another narration it is stated: Such a person will be free from that which was revealed to Muhammad (peace and blessings be upon him).