The obligatory prayer follower following the voluntary prayer leader
Machine translationRead the Arabic original
The questioner:
You say the closing salam. Oh, come pray with me. Yes. You say the closing salam after the prayer. Yes. Oh, come pray with me.
The Shaykh:
There is no harm if you are praying a recommended prayer and someone comes and prays an obligatory prayer with you; it is permissible for the one praying the obligatory prayer to follow the one praying the voluntary prayer. Mu'adh (may Allah be pleased with him) used to pray with the Prophet (peace and blessings be upon him), then he would go out and pray with his congregation; it was a voluntary prayer for him and an obligatory prayer for them, and the Messenger (peace and blessings be upon him) did not disapprove of him. When you say the salam, he stands up and completes his prayer. Good, good. You must raise your voice when you become the imam.
You say the closing salam. Oh, come pray with me. Yes. You say the closing salam after the prayer. Yes. Oh, come pray with me.
The Shaykh:
There is no harm if you are praying a recommended prayer and someone comes and prays an obligatory prayer with you; it is permissible for the one praying the obligatory prayer to follow the one praying the voluntary prayer. Mu'adh (may Allah be pleased with him) used to pray with the Prophet (peace and blessings be upon him), then he would go out and pray with his congregation; it was a voluntary prayer for him and an obligatory prayer for them, and the Messenger (peace and blessings be upon him) did not disapprove of him. When you say the salam, he stands up and completes his prayer. Good, good. You must raise your voice when you become the imam.
Source
شرح بلوغ المرام من أدلة الأحكام [ صالح الفوزان ]، تابع باب المياه - 4 — islamhouse.com (28:02)
The Arabic text is a machine transcription of the audio recording.