‘Aishah (may Allah be pleased with her) related: A necklace of mine fell off at Al-baidaa when we were on our way to Medina. The Prophet (SAW) made his camel kneel, got down, and laid his head on my lap to sleep. Abu Bakr came at me and punched me hard and said: You've held people back because of a necklace! And I played dead because of where the Messenger of Allah (SAW) was, although it hurt me. Then the Prophet (SAW) awoke at the time of the morning [subh] prayer, and water was sought, but none was found, so this verse came down { Oh you who have believed, whenever you arise for prayer } [Al-ma’ida 6] [i.e. permitting tayammum, dry wiping with dust].