I said, O Messenger of Allah, make me the Imam for my people. He said: You are their Imam. So consider the weakest of them and appoint a mu'azthen who does not take any wage for his call to prayer (Azthan).

The Messenger of Allah (PBUH) used to summarize yet complete it, meaning to lighten the prayer.

When one of you leads people in prayer, let him lighten the prayer, for among them are the elderly, the weak, and the sick. And if he prays alone, he can then prolong his prayer as long as he wants.

A man came to the Prophet (PBUH) and said: I keep away from Al-Fajr prayer -in congregation- because of so-and-so, who prolongs the prayer. Narrator added: I did not see the Prophet (PBUH) more angry in a sermon than he was that day. He said: O people, there are some among you who are aversive. So whoever of you leads people in a prayer, he must be brief, for among them are the weak, the elderly, and the one who has an -urgent- affair to attend to.