“and its manner of sitting,” with the letter jim pronounced with a kasrah—for if you were to say, “and its manner of sitting,” with the jim pronounced with a kasrah, that would imply that the particular posture of sitting—namely, iftirāsh—is obligatory. Yet iftirāsh is not obligatory; rather, it is a sunnah. What is obligatory is simply to sit, in whatever manner one may sit.

Ibn Malik (may Allah have mercy on him) says in the Alfiyyah:

The pattern fa‘lah denotes a single occurrence, as in jalsah;

And the pattern fi‘lah denotes a manner, as in jilsah.

When the intended meaning is the description and manner, the pattern fi‘lah, with its first letter pronounced with a kasrah, is used. When a single occurrence is intended, the pattern fa‘lah, with its first letter pronounced with a fatḥah, is used.

What is intended here is the act of sitting, not its particular manner. Thus, if one were to sit cross-legged for the first tashahhud, that would suffice.

His statement, “its sitting”: Is it possible to recite the tashahhud without sitting?

The answer is that one may recite the tashahhud while standing, or while prostrating. Therefore, the entire tashahhud must be recited while sitting.

“Everything other than the aforementioned conditions, pillars, and obligatory elements is sunnah …”

His statement, “Everything other than the aforementioned conditions, pillars, and obligatory elements is sunnah”: The obligatory elements are eight, and their proofs have already been mentioned. However, there is disagreement concerning some of them. Thus, it has been said that the first tashahhud is sunnah (1).

This was argued on the basis that it is waived when omitted forgetfully.

It has likewise been said that the takbirs other than the opening takbir, the tasmi‘—saying that Allah hears whoever praises Him—and the taḥmīd—declaring praise to Allah—are sunnah (2).

This was argued on the basis that the Prophet ﷺ did not mention them to the man who performed his prayer improperly (3).