One of the worst forms of theft or cheating is cheating in prayer.
The Messenger of Allah (pbuh) said:
"The worst type of thief is the one who steals from his prayer."
The people asked, "O Messenger of Allah, how can a person steal from his prayer?"
He said: "By not doing rukoo' and sujood properly."
(Reported by Imaam Ahmad, 5/310; see also Saheeh al-Jaami, 997)
This lack of composure and failure to pause in Rukoo and Sujood (Prostration) and to stand up straight after Rukoo or sit up properly between Sujoods may be observed in many of those who pray, and hardly any mosque is free of examples of people who do not have the proper composure in prayer. Correct composure is one of the pillars of prayer, without which prayer is invalid.
This is a serious matter.
The Prophet (pbuh) said:
"A mans prayer is not good enough until his back is straight in rukoo and sujood."
(Reported by Abu Dawud, 1/533; see also Saheeh al-Jaami', 7224).
Abu Abdullaah al-Ashari reported that the Prophet (pbuh) led his Companions in prayer, then he sat with a group of them. A man came in and started to pray, but made his movements rapid like a chicken pecking the ground.
The Prophet (peace and blessings of Allah be upon him) said: "Do you see this? Whoever dies having done this has died outside of the community of Muhammad, and his prayer is like a crow pecking blood. The person who bows then pecks in his Sujood is like a hungry man who eats no more than one or two dates - what good will that do him?"
(Reported by Ibn Khuzaymah in his Saheeh 1/332; see also al-Albaani, Sifat Salaat al-Nabi (The Prophet's Prayer described), 131)
Zayd ibn Wahb said: "Hudhayfah saw a man who was not performing Rukoo and Sujood properly.
He said: You have not prayed, and if you were to die, you would die on a way other than that revealed by Allah to Muhammad (pbuh)
(Reported by Al-Bukhaari, see Al-Fath, 2/274).
Once a person is aware of this ruling, if he fails to perform prayer with the proper composure, he should repeat it and repent to Allah for what is past; he does not need to repeat all of his previous prayers, as is indicated by the Hadeeth
"Repeat your prayer, for you have not prayed."
`Ata' bin Dinar said, "All praise is due to Allah, the One Who said, (with their Salah are Sahun) and He did not say,
"Those who are absent minded in their prayer. It could also mean the first time of the prayer, which means they always delay it until the end of its time, or they usually do so. It may also refer to not fulfilling its pillars and conditions, and in the required manner. It could also mean performing it with humility and contemplation of its meanings. The wording of the Ayah comprises all of these meanings. However, whoever has any characteristic of this that we have mentioned then a portion of this Ayah applies to him. And whoever has all of these characteristics, then he has completed his share of this Ayah, and the hypocrisy of actions is fulfilled in him.
This is just as is confirmed in the Two Sahihs that the Messenger of Allah [sal Allaahu Alayhi wa sallam] said, (This is the prayer of the hypocrite, this is the prayer of the hypocrite, this is the prayer of the hypocrite. He sits watching the sun until it is between the two horns of Shaytan. Then he stands and pecks four (Rak`ahs) and he does not remember Allah (in them) except very little)
