Furthermore, He—Glorified is He—said:

“The only ones who believe in Our signs are those who, when reminded of them, fall down in prostration, glorify their Lord with praise, and are not arrogant.” [al-Sajda: 15] [al-Sajda]

He thus stated that no one is a believer except one who prostrates when reminded of the signs and glorifies his Lord with praise.

It is well known that reciting the Quran in prayer constitutes a reminder of the signs. This is why prostration is obligatory along with it. He made their falling down in prostration obligatory, as well as their glorifying their Lord with praise. This entails that glorification during prostration is obligatory, which in turn entails the obligation of stillness. Hence, a group of scholars—including some of Ahmad’s followers and others—said: The required duration of stillness is the duration of the glorification that they hold to be obligatory.

Second, khurūr denotes falling or dropping down. This is said only of that which comes to rest and becomes still, not of that which never comes to rest upon the ground. Hence Allah said, “When they have fallen upon their sides” [al-Hajj: 36]. The root meaning of wujūb is being fixed and settled.

Furthermore, Uqba ibn Āmir—may Allah be pleased with him—reported: “When the verse, ‘So glorify the name of your Lord, the Most Great’ [al-Wāqi'a: 74] [al-Wāqi'a], was revealed, the Messenger of Allah—peace and blessings be upon him—said, ‘Make it part of your bowing.’ When the verse, ‘Glorify the name of your Lord, the Most High’ [al-A'lā: 1], was revealed, he said, ‘Make it part of your prostration.’” Narrated by Abu Dāwūd and Ibn Mājah.

The Prophet—peace and blessings be upon him—thus commanded that these two glorifications be included in bowing and prostration. His command signifies obligation, and this entails that the bowing and prostration must be maintained for the duration of this glorification. That is stillness.