"What was the Divine Verse of Tayammum revealed in response to Abu Bakr's admonition of 'Aisha, when Allah's Apostle (peace be upon him) was sleeping with his head on her thigh?"
 Narrated `Aisha:                     Abu Bakr came to me while Allah's Apostle was sleeping with his head on my thigh. Abu Bakr said (to me), "You have detained Allah's Apostle and the people, and there is no water in this place." So he admonished me and struck my flanks with his hand, and nothing could stop me from moving except the reclining of Allah's Apostle (on my thigh), and then Allah revealed the Divine Verse of Tayammum.