Narrated Abu Mas`ud: A man came and said, O Allah's Apostle! I keep away from the morning prayer because so-and-so (Imam) prolongs it too much. Allah's Apostle became furious and I had never seen him more furious than he was on that day. The Prophet said, O people! Some of you make others dislike the prayer, so whoever becomes an Imam he should shorten the prayer, as behind him are the weak, the old and the needy.''