Al-aib ("the rump bone," os coccygis). The Koran teaches that a man's body is entirely consumed by the earth, excepting only the al-aib, which is to form the basis of a new body. The renewal of the whole human frame is to be effected by a forty days rain, which will cover the earth to the height of twelve cubits, and cause the bodies to spring. up like plants. But the time of the resurrection is to them a perfect secret, known only to God; the angel Gabriel himself acknowledging his ignorance on this point when Mohammed asked him.