The ruling on the prayer of one who enters the second rak'ah behind the row
Machine translationRead the Arabic original
Question:
Honorable Shaykh, he says: I prayed alone behind the row, and a person came and joined me in the second rak'ah. Is it permissible for me to point this out to him after he has finished his prayer?
Answer:
Why did you pray behind the row? You are the one who deceived him. Why do you pray behind the row without an excuse? Neither of your prayers is valid. Yes.
Honorable Shaykh, he says: I prayed alone behind the row, and a person came and joined me in the second rak'ah. Is it permissible for me to point this out to him after he has finished his prayer?
Answer:
Why did you pray behind the row? You are the one who deceived him. Why do you pray behind the row without an excuse? Neither of your prayers is valid. Yes.
Source
نور على الدرب - الفوزان - 03/086 — archive.org (11:31)
The Arabic text is a machine transcription of the audio recording.