Mālik said, “The adhān that is given directly in front of the imam is not part of the earliest practice.” Others replied, “On the contrary, that is the original Friday adhān, and only what can truly be called a khutbah fulfils the requirement; this is the soundest opinion on the matter.”
If the imam delivers the entire sermon—or even part of it—while not in a state of ritual purity, he acts wrongly, yet he is not required to repeat it so long as he performs the prayer itself in a state of purity.
The brief sitting between the two sermons is a sunnah, and so is the sitting that precedes the first sermon. Some scholars, however, hold that the pre-sermon sitting is merely recommended (mustaḥabb) rather than an established sunnah.
Remaining silent during the khutbah is obligatory for anyone who hears it, with the binding force of a sunnah. The sunnah further dictates that those who can hear the sermon and those who cannot should all keep silent; God willing, their reward is the same. Whoever speaks at that time has lapsed into idle talk, yet his prayer is not thereby invalidated.
In the Friday prayer, after the Opening Chapter (al-Fātiḥah), one should recite Sūrah al-Jumuʿah in the first rakʿah, and in the second either “Glorify the Name of your Lord, the Most High” (Sūrah al-Aʿlā), “Has there come to you the report of the Overwhelming One?” (Sūrah al-Ghāshiyah), or “When the hypocrites come to you” (Sūrah al-Munāfiqūn). All of these choices are good and recommended, and the imam may recite whatever he wishes; nevertheless, Sūrah al-Jumuʿah should not be omitted except out of necessity. If he recites something else without such necessity, the prayer is still valid but he has acted improperly.
If the imam begins the Friday prayer with a large, complete congregation and they disperse until only two worshippers remain in addition to himself, he still completes it as a Friday prayer. Another view maintains that he should finish it as Jumuʿah only if the minimum number required for Friday remains; otherwise he must complete it as ẓuhr. A third opinion says that once he has completed one rakʿah with the congregation necessary for Jumuʿah and they then leave him alone, he should finish the prayer as Friday. The first of these views is Mālik’s.
Whoever catches one rakʿah of the Friday prayer with the imam adds one more rakʿah and the prayer counts as Jumuʿah. Whoever misses that rakʿah has missed the Friday prayer altogether and must pray ẓuhr on his own.