What did Abdullah feel when he realized he wanted to sit down and leave the Prophet Muhammad (saw) standing during tahajjud prayer?
 Narrated Abu-Wail:                     `Abdullah said, "One night I offered the Tahajjud prayer with the Prophet and he kept on standing till an ill-thought came to me." We said, "What was the ill-thought?" He said, "It was to sit down and leave the Prophet (standing)."