Ibn ‘Abbas said that God’s Messenger prolonged the recitation of the Qur’an in the two rak'as after the sunset prayer till the people in the mosque separated.
Ka‘b b. ‘Ujra said that the Prophet came to the mosque of the B. ‘Abd al-Ashhal and prayed the sunset prayer in it. When the people finished their prayer he saw them performing tasbih after it and said, “This is the prayer to be observed at home.”*
* This refers to supererogatory prayers. Tasbih is the utterance of 'Glory be to God!’
Abu Dawud transmitted it. In the version by Tirmidhi and Nasa’i it says that the people got up and offered supererogatory prayers, whereupon the Prophet said, “Observe this prayer at home.”
Makhul, tracing it back, told how God’s Messenger said, “If anyone before engaging in conversation after the sunset prayer prays two rak'as (four rak'as according to another version), his prayer will be taken up to ‘Illiyun.” It is given in mursal form. Hudhaifa has something similar, adding that he used to say, “Hasten the two rak'as after the sunset prayer, for they will be taken up along with the prescribed prayer.”
Razin transmitted them both, and Baihaqi transmitted something to the same effect as the addition in Shu'ab al-iman.
I went to ‘Uqba al-Juhani and said, “I can tell you something about Abu Tamim which will make you wonder. He prays two rak'as before the sunset prayer.” ‘Uqba replied, “We used to do so in the time of God’s Messenger.” I asked, “What prevents you now?” and he replied, “Work.”