This hadith indicates that performing these rak‘ahs is recommended—and indeed that they should be observed regularly—in the hope of being included in the supplication of the Messenger of Allah—peace and blessings be upon him.
Third: Its Manner:
The regular Sunnah prayer of Asr consists of four rak‘ahs performed together, with two tashahhuds, as in other four-rak‘ah prayers. The final salām is given at the end of all four, and they are performed before the Asr prayer.
Āsim ibn Damrah al-Salūlī reported: We asked Alī about the voluntary prayers of the Messenger of Allah—peace and blessings be upon him—during the day. He replied, “You would not be able to maintain them.” We said, “Tell us about them, and we will perform as much as we can.” He said:
“The Messenger of Allah—peace and blessings be upon him—would wait after performing the Fajr prayer until the sun in the east reached the same elevation that it reaches in the west at the time of the Asr prayer. He would then rise and perform two rak‘ahs. He would then wait until the sun in the east reached the same position that it reaches in the west at the time of the Dhuhr prayer, whereupon he would rise and perform four rak‘ahs. He would also perform four rak‘ahs before Dhuhr after the sun had passed the meridian, two rak‘ahs afterward, and four rak‘ahs before Asr. Between every two rak‘ahs, he would greet with peace the angels brought near, the prophets, and those Muslims and believers who followed them.”
Alī said, “These were the sixteen rak‘ahs that the Messenger of Allah—peace and blessings be upon him—performed voluntarily during the day, yet few people observe them regularly.” Recorded by al-Tirmidhī and Ibn Mājah.
According to a narration recorded by al-Nasā’ī: “The Messenger of Allah—peace and blessings be upon him—would perform two rak‘ahs when the sun passed the meridian and four rak‘ahs before midday, giving the final salām at their conclusion.” (1)