A group of scholars, including Imām Mālik, Imām Shāfiʿī, and among them Imām Bukhārī, have considered the incident in which the Prophet (peace and blessings be upon him) led the prayer sitting, while Abū Bakr stood and followed him, and the congregation behind followed Abū Bakr, as an abrogating (nāsikh) event for the hadith we will relate below. For on one occasion, when the Prophet (peace and blessings be upon him) fell from a horse and injured his side, he led his Companions (ṣaḥāba) in prayer while sitting. His Companions, however, prayed behind him standing, following him. But the Messenger of God (peace and blessings be upon him) signaled to them to sit down. After completing the prayer, he said:
"By Allah, in Whose hand is my soul, you have done as the Persians and the Byzantines do. Their leaders sit while they themselves stand in prayer. Yet the imam is to be followed. If he pronounces the takbīr, you also pronounce the takbīr. If he bows, you also bow. If he rises from bowing, you also rise. If he prostrates, you also prostrate. If he prays sitting, then all of you should pray sitting together."
They said: During the Prophet's (peace and blessings be upon him) final illness, he led the congregation in prayer while sitting. The congregation, however, prayed standing. This indicates that the latter incident abrogated the earlier hadith. Allah knows best.
People have responded to this inference in different ways. God willing, we will explain these in the book "al-Aḥkām al-Kabīr." Our refuge and reliance is upon Allah.
This can be summarized as follows: Some people have said that the Companions (ṣaḥāba) prayed sitting because of the Prophet's (peace and blessings be upon him) earlier command. Abū Bakr continued to pray standing in order to convey the takbīrs, movements, and pauses of the Prophet (peace and blessings be upon him) to the congregation.
Some people have also said: In fact, in that prayer, Abū Bakr was the one acting as imam. Out of great respect for the Messenger of God (peace and blessings be upon him), Abū Bakr did not move before him; rather, he followed him in the movements of the prayer. In this case, the Prophet (peace and blessings be upon him) became like the imam of the imam. Therefore, since the congregation was following Abū Bakr, they did not sit, because Abū Bakr was praying standing. As Abū Bakr was the imam and was conveying the movements, pauses, and transitions of the Prophet (peace and blessings be upon him) to the congregation, he did not sit. Allah knows best.
Some people have also said: There is a difference between beginning the prayer standing behind the imam, continuing the prayer standing, and, due to some reason, the imam then praying sitting, and between starting the prayer behind an imam who is already sitting. In this case, because of the earlier hadith, it becomes obligatory for the follower to sit. Allah knows best. Some people have also said: Both this and the previous hadith indicate the permissibility of both standing and sitting. Just as sitting is permissible due to the earlier hadith, so too is standing permissible due to the action of the Messenger of God (peace and blessings be upon him) described in the latter part. Allah knows best.