The reason for the disagreement is that two seemingly divergent ḥadīths exist on the point.

The first is the sound report of Mālik ibn al-Huwayrith:
“I saw the Messenger of Allah—peace and blessings be upon him—performing the prayer, and whenever he was in an odd-numbered unit he would not rise until he had first sat upright.”

The second is the ḥadīth of Abū Humayd describing the Prophet’s prayer—peace and blessings be upon him:
“When he lifted his head from the second prostration of the first rakʿah, he stood up without sitting back.”

Al-Shāfiʿī built his ruling on the first report, whereas Mālik relied on the second.

They likewise differed over the manner of going down into prostration: should one place the hands before the knees, or the knees before the hands? The Mālikī position is to place the knees first.

The reason for their divergence here is that Waʾil ibn Ḥujr narrated:
“I saw the Messenger of Allah—peace and blessings be upon him—when he prostrated, put his knees down before his hands; and when he rose he lifted his hands before his knees.”

On the other hand, Abū Hurayrah related that the Prophet—peace and blessings be upon him—said:
“When any of you goes to prostrate, let him not drop the way a camel drops; rather let him place his hands before his knees.”

ʿAbd Allāh ibn ʿUmar used to put his hands down before his knees, and some ḥadīth scholars held that the report of Waʾil ibn Ḥujr is more reliable than that of Abū Hurayrah.

Issue Seven
The scholars unanimously agree that prostration is to be performed on seven limbs: the face, the two hands, the two knees, and the tips of the two feet, based on the Prophet’s statement—peace and blessings be upon him—“I have been commanded to prostrate on seven limbs.”

They disagreed, however, about a person who prostrates on his face but omits one of the other limbs: does this invalidate the prayer or not?
• One group held that the prayer is not invalid, because the term “prostration” in its primary sense refers only to the face.
• Another group maintained that the prayer is invalid if he does not prostrate on all seven limbs, in deference to the authentic ḥadīth.

All are agreed that whoever prostrates on both his forehead and nose together has indeed prostrated on his face. They differed, though, about someone who prostrates on only one of the two:
• Mālik said: If he prostrates on his forehead without his nose, it is valid; but if on his nose without his forehead, it is not.
• Abū Ḥanīfah held that either way is acceptable.
• Al-Shāfiʿī ruled that it is not acceptable unless he prostrates on both together.