The ruling on the extra rak'ah due to forgetfulness by the imam
Machine translationRead the Arabic original
Question:
The questioner says: Shaykh, a man joined the congregation and had missed a rak'ah, and the imam added a rak'ah by mistake. Does he say the taslim with the imam, or does he perform the rak'ah he missed?
Answer:
He does not say the taslim with the imam. This rak'ah is not part of the prayer; it is an extra rak'ah, not for the imam, nor for the congregation of ma'mums, nor for those who joined late. It does not count as anything. When the imam says the taslim, he stands up and performs what he missed. Yes.
The questioner says: Shaykh, a man joined the congregation and had missed a rak'ah, and the imam added a rak'ah by mistake. Does he say the taslim with the imam, or does he perform the rak'ah he missed?
Answer:
He does not say the taslim with the imam. This rak'ah is not part of the prayer; it is an extra rak'ah, not for the imam, nor for the congregation of ma'mums, nor for those who joined late. It does not count as anything. When the imam says the taslim, he stands up and performs what he missed. Yes.
Source
نور على الدرب - الفوزان - 03/057 — archive.org (11:53)
The Arabic text is a machine transcription of the audio recording.