The Messenger of Allah ﷺ asked, "What do you say about the one who drinks wine, the thief, and the fornicator?" This was before the penalties concerning them had been revealed.They replied, "Allah and His Messenger know best."He said, "They are grave sins, and there is punishment for them. But the worst theft is that of a man who steals from his own prayer."They asked, "How does a man steal from his own prayer, Messenger of Allah?"He answered, "He does not complete its bowing or its prostration."
و حدثني عن مالك عن يحيى بن سعيد
أن رسول الله ﷺ قال ما ترون في الشارب والسارق والزاني وذلك قبل أن ينزل فيهم قالوا الله ورسوله أعلم قال هن فواحش وفيهن عقوبة وأسوأ السرقة الذي يسرق صلاته قالوا وكيف يسرق صلاته يا رسول الله قال لا يتم ركوعها ولا سجودها