Ruwaifi' b. Thabit told that God’s messenger said to him, “You may live for a long time after I am gone, Ruwaifi', so tell people that if anyone ties his beard, or wears round his neck a string to ward off the evil eye, or cleanses himself with animal dung or bone, Muhammad has nothing to do with him. Abu Dawud transmitted it.

وَعَن رويفع بن ثَابت قَالَ: قَالَ لِي رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: يَا رُوَيْفِعُ لَعَلَّ الْحَيَاةَ سَتَطُولُ بِكَ بَعْدِي فَأَخْبِرِ النَّاسَ أَنَّ مَنْ عَقَدَ لِحْيَتَهُ أَوْ تَقَلَّدَ وَتَرًا أَوِ اسْتَنْجَى بِرَجِيعِ دَابَّة أَو عظم فَإِن مُحَمَّدًا بَرِيء مِنْهُ. رَوَاهُ أَبُو دَاوُد