whoever among you leads the people in prayer should shorten it
Narrated Abu Mas`ud may Allah be pleased with him:
A man came and said, "O Allah's Messenger! By Allah, I keep away from the morning prayer only because So and so prolongs the prayer when he leads us in it." The narrator said, "I never saw Allah's Messenger, may the peace and blessings of Allah be upon him, more furious in giving advice than he was at that time. He then said, "Some of you make people dislike good deeds (the prayer). So whoever among you leads the people in prayer should shorten it because among them are the weak, the old and those who have some jobs to do."
The Prophet, may the peace and blessings of Allah be upon him, loved easiness in everything, if he was to choose between two things he would choose the easier one, unless it incurs sin. His companions, may Allah be pleased with them, knew that, so they dislike and reject that a man overburdens them or even himself in a matter or in an act of worship when they saw that he persists on this approach, they would raise the matter to the Messenger of Allah, may the peace and blessings of Allah be upon him, to guide him to the right way. One of the companions, may Allah be pleased with them, prayed behind an imam who prolonged the prayer to the extent that this companion disliked to offer the prayer behind him, but he feared that his failure to pray with the congregation corrupts it, or that it may be a sedition for those who pray behind him or that he is disobedient to the messenger of Allah and went out of the group of Muslims. He consulted the Messenger of Allah, may the peace and blessings of Allah be upon him, and said: O Messenger of Allah, by Allah I keep away from the morning prayer only because So and so prolongs the prayer when he leads us in it