What was the sign that the Prophet Muhammad (saw) gave to identify those who would desert Islam?
 Narrated Abu Sa`id Al-Khudri:                     While the Prophet was distributing (war booty etc.) one day, Dhul Khawaisira, a man from the tribe of Bani Tamim, said, "O Allah's Apostle! Act justly." The Prophets said, "Woe to you! Who else would act justly if I did not act justly?" `Umar said (to the Prophet ), "Allow me to chop his neck off." The Prophet said, "No, for he has companions (who are apparently so pious that) if anyone of (you compares his prayer with) their prayer, he will consider his prayer inferior to theirs, and similarly his fasting inferior to theirs, but they will desert Islam (go out of religion) as an arrow goes through the victim's body (games etc.) in which case if its Nasl is examined nothing will be seen thereon, and if its Nady is examined, nothing will be seen thereon, and if its Qudhadh is examined, nothing will be seen thereon, for the arrow has gone out too fast even for the excretions and blood to smear over it. Such people will come out at the time of difference among the (Muslim) people and the sign by which they will be recognized, will be a man whose one of the two hands will look like the breast of a woman or a lump of flesh moving loosely." Abu Sa`id added, "I testify that I heard that from the Prophet and also testify that I was with `Ali when `Ali fought against those people. The man described by the Prophet was searched for among the killed, and was found, and he was exactly as the Prophet had described him." (See Hadith No. 807, Vol. 4)