Translation by @aboo_aamir
The khateeb - that we call the Imaam - ought to have a good number of positive triats before he is made an Imaam over the people.
1. He should be upright in accordance with the Aqeedah and Manhaj of Ahlus Sunnah Wal Jama'ah lest he misleads the people.
2. He should have necessary knowledge of the Islamic jurisprudence with respect to how to observe the Salaah and other aspects of the Islamic rulings.
3. He should have the adequate knowledge about the Arabic Language especially the knowledge of how to make far-reaching compositions that can touch the hearts but not flamboyant, flowery and pretentious.
4. He should understand his audience such that he knows when to command and forbid.
5. He should be righteous, abstemious, command respect, and contented. He should not be an open sinner or someone who indulges in contravention of the sharee'ah.
Adapted partly from Al Qawl Al Mubeen Fee Akhtaail Musalleen pp. 373-374