‘Awwam (may Allah have mercy on him) narrates: Mujahid (may Allah have mercy on him) said to me:“On what is the prostration (sajdah) of Surah Sad?”He replied:“Allah, the Mighty and Majestic, mentioned the Prophets, then said: ‘Those are the ones whom Allah has guided, so follow their guidance’ (__QUR_N__). So the Messenger of Allah (peace and blessings be upon him) followed their example, and we followed the example of the Messenger of Allah (peace and blessings be upon him).”

Mujahid (may Allah have mercy on him) says: I said to Sayyiduna Ibn Abbas (may Allah be pleased with them): We perform sajdah (prostration) in Surah Sad! So he recited the verse: "Those are the ones whom Allah has guided, so by their guidance take example." (__QUR_N__), and said: Sayyiduna Dawud (peace be upon him) is among those prophets whom your Prophet (peace be upon him) was commanded to follow.