It has been answered that the ḥadith of Ibn ʿUmar has been unanimously judged weak by the ḥadith masters. Al-Tirmidhi remarked, “This report’s chain of transmission is not particularly strong.” As for the ḥadith of the man who prayed poorly, it does not negate the obligation, for the requirement of the taslīm is an additional element—and a reliable addition is accepted.

Accordingly, the majority of the Companions and Successors—and, among the jurists, the Shāfiʿīs and Ḥanbalīs—consider the taslīm obligatory. They reason that the Prophet ﷺ consistently performed it, coupled with his instruction, “Pray as you have seen me pray,” and with the authentic statement found in the Sunan collections: “Its opening is the takbīr, and its closing is the taslīm.”

Hadith Three
ʿAbd Allāh ibn ʿUmar (may Allah be pleased with them both) reported that the Prophet ﷺ used to raise his hands level with his shoulders when he began the prayer, when he said the takbīr for bowing, and when he lifted his head from bowing he raised them the same way and said, “Allah hears the one who praises Him; our Lord, to You belongs all praise.” He did not do that during prostration.

General meaning
The prayer is a noble banquet that gathers every wholesome delight; each limb of the body has its own act of worship within it. Among these are the two hands: part of their role is to be raised at the opening takbīr as an adornment for the prayer, a sign of entering into the Divine presence, and a lifting of the veil of heedlessness that separates the worshipper from his Lord. The hands are to be raised until they are parallel with the shoulders; they are raised again at every bowing in all rakʿahs, and when the worshipper lifts his head from bowing in every rakʿah. This ḥadith explicitly states, through its narrator, that the Prophet ﷺ did not raise them in prostration.

Scholarly disagreement
The scholars unanimously agree on the prescription of raising the hands at the opening takbīr, for the reports attesting to it are mass-transmitted: it has been narrated by fifty Companions, including the ten who were promised Paradise. They differ, however, regarding raising the hands at other points in the prayer.