Sahih Muslim 738e

“Kufah was conquered by a man called Zamān ibn al-Ash‘ath. He ordered Abu ‘Ubaydah ibn ‘Abdullāh to lead people in prayer.” This man was Matar ibn Nājiyah, as he was called in another narration. Abu ‘Ubaydah was the son of ‘Abdullāh ibn Mas‘ūd (may Allah be pleased with him).

“When he performed the prayer, he would rise from bowing and stand for as long it took me to say: "O Allah, our Lord, to You is all praise…" This amount of time is one of the requirements of prayer. As for the addition: “…that fills the heavens…” this is recommended according to the Prophet’s statement: "When the Imām says, 'Allah hears he who praises him,' say: 'Our Lord, to You is all praise.’”

"O Allah, our Lord, to You is all praise" is a supplication and acknowledgement, meaning: Our Lord, answer our invocations, and all praise is due to You for leading us to guidance and success.

"…that fills the heavens and the earth" is meant to magnify the amount of praise. In other words: Our Lord, You deserve such praise that, if it were bodies, would fill all that space.

“…and whatever You will beyond that”, meaning: what we do not know of Your vast dominion. “All praise and glory belong to You”, meaning: Our Lord, You deserve all praise (commendation) and glory (greatness, power, and supreme honor). The Only One worthy of absolute commendation and exaltation is Allah, the Almighty.

“No one can withhold what You have given…”, meaning: no one can prevent what You want to give. “…and no one can give what You have withheld”, meaning: no one can give what You will to withhold, out of Your wisdom and justice.

“And the good fortune of a person will not avail him before You”, meaning: The wealth and good fortune of a person does not benefit him in Your sight, earn him any reward, or save him from punishment. Indeed, nothing is beneficial, except if so willed by You.

Al-Hakam added: "I mentioned that to ‘Abdur-Rahmān ibn Abu Layla and he said: ‘I heard Al-Barā' ibn ‘Āzib say: “In the prayer of the Messenger of Allah (may Allah's peace and blessings be upon him), the bowing, rising from bowing, prostration, and sitting between the two prostrations were all roughly the same (in length).”’” This means that the pillars of the Prophet’s prayer lasted similar lengths of time and there was only a slight difference between them.

If he prolonged his standing, he would bow for a length of time close to it, and the same would happen with the other pillars. Conversely, when he shortened his standing, he would also shorten his bowing, making it close in length to the standing. And the same applied to the other pillars. This Hadīth is understood to refer to some instances only, as the Prophet (may Allah's peace and blessings be upon him) would occasionally prolong his prayer.

In short, the Prophet’s prayers were of a similar length of time. So his bowing, rising from bowing, prostration, and sitting between the two prostrations were nearly the same length, but he would sometimes prolong the standing for the Qur’an recitation.