Abu Qatada said that in the first two rak'as of the noon prayer the Prophet used to recite Umm al-Kitab and two suras, and in the last two rak'as Umm al-Kitab, and he would sometimes recite loud enough for them to hear the verse. He would prolong the first rak'a more than the second; and he acted similarly in the afternoon and the Morning Prayer.
Narrated Abu Musa al-Ash‘ari reported God’s Messenger as saying:
When you pray make your rows straight and let one of your number act as your imam. If you say the takbir when he says it and say Amen when he says “Not of those with whom Thou art angry nor of those who go astray”, God will accept your prayer. When he says the takbir and bows, say it and bow, for the imam bows before you and raises himself before you. Then God’s Messenger said, “The one is equivalent to the other.”* And he said: If you say, “O God our Lord, to Thee be the praise,” when he says, “God listens to him who praises him,” God will listen to you.
* Although the imam begins and ends his bowing before you do, your bow lasts the same length of time as his.
Muslim transmitted it. In a version by him from Abu Huraira and Qatada the words occur, “And when he recites listen silently.”
Abu Sa'id al-Khudri said, “We used to estimate how long God’s Messenger stood at the noon and the afternoon prayer, and we estimated that he stood in the first two rak'as as long as it takes to recite A.L.M. Tanzil, i.e. as-Sajda* (A version has, “In every rak'a as long as it takes to recite thirty verses.” We estimated that he stood half that time in the last two rak'as; that he stood in the first two of the afternoon prayer as long as he did in the last two at noon; and in the last two of the afternoon prayer about half that time.”
Abu Huraira reported God’s Messenger as saying, “Say Amen when the imam says it, for if anyone’s utterance of Amen synchronises with that of the angels, he will be forgiven his past sins. ’
(Bukhari and Muslim.) In a version he said, “When the imam says, ‘Not of those with whom Thou art angry nor of those who go astray’, say Amen, for if anyone’s words synchronise with those of the angels he will be forgiven his past sins.” This is Bukhari’s wording, and Muslim has something similar. In another version by Bukhari he said, “Say Amen when the reciter (i.e. the imam) says it, for the angels do so, and if anyone’s utterance of Amen synchronises with that of the angels, he will be forgiven his past sins.”
