The ruling on continuing the prayer upon hearing a second congregation
Machine translationRead the Arabic original
The questioner:
The Shaykh said: In the Maghrib prayer, one entered the mosque and saw that the prayer was shorter than the prayer in progress. We heard the sound of a second congregation, and we did not know whether they had arrived before our prayer or after it. Our esteemed professor, then you say: In this case, do we continue the prayer or break it off? Or do we pray the second congregation?
The Shaykh:
As long as you joined a congregation and did not know of a congregation before you, continue your prayer; it is valid, if Allah wills. Yes.
The Shaykh said: In the Maghrib prayer, one entered the mosque and saw that the prayer was shorter than the prayer in progress. We heard the sound of a second congregation, and we did not know whether they had arrived before our prayer or after it. Our esteemed professor, then you say: In this case, do we continue the prayer or break it off? Or do we pray the second congregation?
The Shaykh:
As long as you joined a congregation and did not know of a congregation before you, continue your prayer; it is valid, if Allah wills. Yes.
Source
شرح بلوغ المرام من أدلة الأحكام [ صالح الفوزان ]، تابع باب صلاة الجماعة والإمامة - 1 — islamhouse.com (54:24)
The Arabic text is a machine transcription of the audio recording.