It is narrated from Hazrat Ruwaifi’ (may Allah be pleased with him) that during the blessed era of the Prophet (peace be upon him), we used to participate in jihad. Among us, a person would take a camel from another on the condition that he would give half of his share from the spoils of war to the owner of the she-camel. Sometimes, one of us would only have a strap, and another would have fruits and feathers. The Prophet (peace be upon him) said to me,“O Ruwaifi’! It may be that you live a long life, so inform people that whoever ties a knot in his beard, or hangs a string around his neck, or uses the dung or bone of an animal for istinja (purification), then Muhammad (peace be upon him) is free from such a person.”