Nasai

1211. Commentary: In all four of the above-mentioned narrations, it is stated that men should say "Subhan Allah" and women should clap their hands.

1208. Commentary: Benefit: See, Hadith: 785.

Hadith Commentary:

Qastallani said that a woman should clap in such a manner that the palm of her right hand strikes the back of her left hand. If, as a form of play, she strikes the palm of her left hand, her prayer (salah) will become invalid. And if a man, due to ignorance of the ruling, also claps, his prayer will not become invalid, because the Messenger of Allah (sallallahu alayhi wa sallam) did not command those Companions (radi Allahu anhum) who had unknowingly clapped to repeat their prayer.
(Wahidi)

English Commentary:
1:
From this hadith, it is understood that when the imam makes a mistake in prayer, men should alert him by saying "Subhan Allah," while women should alert him not by saying anything verbally, but by striking the palm of their right hand on the back of their left hand. Some people alert the imam by saying "Allahu Akbar" instead of "Subhan Allah"; this is not established from the Sunnah.

939. Commentary:
Hafiz Ibn Hajar rahimahullah states that if the imam needs to be alerted to something during the prayer, the Sunnah is that men should say «سبحان الله», but women should clap, striking the back of their left hand with their right hand, and not in the manner of the well-known clap, because that is amusement and play, and amusement and play are not permissible in prayer. Women are prohibited from saying tasbih so that their voices do not become a cause of temptation (fitnah), and men are prohibited from clapping because that is the practice of women. [عون المعبود]

Takhrij al-Hadith
[سنن ابي داود 944، سنن الدارقطني : 83/2، شرح معاني الآثار للطحاوي : 453/1]

Fiqh al-Hadith
↰ This hadith is "weak" (da'if). In its chain is Muhammad ibn Ishaq «حسن الحديث، ثقه الجمهور», who is a well-known "mudallis" (one who practices tadlis), and he is narrating with the wording «عن», with no explicit statement of hearing (sama') found. Furthermore, it is also contrary to "authentic" (sahih) ahadith.

944. Commentary:
Because indicating by gesture as needed is established from authentic ahadith.

Benefits and Issues:

➊
If the imam makes a mistake during the prayer, he should be alerted by saying "Subhan Allah."

➋
If no man indicates the imam’s mistake, then women may also alert the imam to his mistake.

➌
However, women should not say "Subhan Allah."
Rather, they should strike one hand against the back of the other hand.

➍
This indicates that a woman should not raise her voice to men without necessity.

➎
In some rulings of prayer, there is a difference between men and women; this issue is also among them.

Lexical Explanation:
«اَلتَّسْبِيحُ لِلرِّجَالِ» When a worshipper wishes to inform and alert the imam about an unexpected situation or a mistake during prayer, he should say "Subhan Allah" to notify the imam of his error. And if it is a woman, she should clap, in such a manner that she strikes the back (outer side) of her left hand with two fingers of her right hand.

Benefits and Issues:
➊ When the imam forgets during the prayer, the male follower should say «سُبْحَانَ الله» to alert him to his mistake, and if the follower is a woman, she should notify by clapping. She should not say «سُبْحَانَ الله» or similar phrases verbally.
➋ Isa bin Ayyub has described the manner of clapping as striking two fingers of the right hand on the back (outer side) of the left hand.
➌ Some ignorant people, instead of saying «سُبْحَانَ الله», say «اللهُ أَكْبَر» to alert the imam. This is not correct because it is not established from the Sunnah.

Benefit:
From this hadith, it is understood that when the male imam makes a mistake, the follower (muqtadi) should say "Subhan Allah," and when a woman wishes to respond, women should clap. The manner of this is that a woman will strike the back of one hand against the other.