Musannaf Ibn Abi Shaybah

Hazrat Saeed bin Musayyib says that if I offer prayer at home, then I come to a mosque where congregation is being held and I get one rak'ah with that congregation, that one rak'ah is more beloved to me than the entire prayer offered alone.

Hazrat Saeed bin Musayyib says that his obligatory prayer will be the one which he performed with the congregation.

Hazrat Ata says that if a person offered prayer in congregation, while he had already performed the prayer alone, then his obligatory prayer will be the second one.

Hazrat Saeed bin Musayyib says that the obligatory prayer is the one that is performed in congregation.

Hazrat Ali (may Allah be pleased with him) says that its obligatory prayer is the first prayer.