Ruku, sujud and the remembrance in them

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Indeed, Allah, the Blessed and Exalted, does not look with favour at the prayer of a servant who does not keep his lower garment above his ankles (out of arrogance), and who does not place both his palms on the ground (in prostration)."
The narrator named Jabir al-Ju'fi is matruk al-hadith (abandoned in hadith).

It is narrated from Sayyiduna Abu Abdullah al-Ash'ari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) passed by a man who was not completing his bowing and his prostration (in prayer). He (peace and blessings be upon him) said: "If this man dies in this state, he will die upon a way other than the religion of Muhammad (peace and blessings be upon him)." Then, describing the state of bowing and prostration, he (peace and blessings be upon him) said: "Indeed, the likeness of the one who prays but does not perform his bowing and prostration fully is like a hungry person who eats only one or two dates, which do nothing to remove his hunger."
Abu Salih said: I met Sayyiduna Abu Abdullah (may Allah be pleased with him) and asked: "Who narrated this hadith to you? Or did you hear it yourself?" He replied that he had heard it from the Messenger of Allah (peace and blessings be upon him) himself, and the commanders of the armies, Sayyiduna Khalid bin al-Walid, Sayyiduna Shurahbil bin Hasanah and Sayyiduna Amr bin al-As (may Allah be pleased with them), also confirmed that they had heard it from the Messenger of Allah (peace and blessings be upon him) themselves.

It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said to a man: "When you bow, place both your hands on your knees and keep space between your fingers (that is, keep them spread apart)."
[Takhrij: Musnad Ibn Abi Umar: 504. Its chain contains Isma'il bin Rafi', who is da'if (weak), and it has an unnamed (unknown) narrator; however, the instruction to grasp the knees with the hands in bowing and to keep the fingers spread is established by other authentic hadith.]

It is narrated from Sayyar bin al-Maghrur (may Allah have mercy on him) that he said: I heard the Commander of the Believers, Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), delivering a sermon, and he was saying: "O people! Indeed, the Messenger of Allah (peace and blessings be upon him) built this mosque while we, the Muhajirun and the Ansar, were with him (peace and blessings be upon him). So when the crowding and throng becomes very heavy (during the prayer), let each one of you prostrate on the back of his brother (in front of him)." He also saw some people praying in the road and ordered them: "Offer your prayer inside the mosque."
Abu Bakr bin Abi Shaybah also transmitted this report by way of Abu al-Ahwas, but his narration goes only as far as the words: "let him prostrate on the back of his brother."

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him): "Indeed, when the Messenger of Allah (peace and blessings be upon him) prostrated, the whiteness of his (peace and blessings be upon him) armpits could be clearly seen."
Musaddad recorded this hadith, and its narrators are thiqat (trustworthy).

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that he said: "On a rainy day I saw the Messenger of Allah (peace and blessings be upon him) (in prayer) protecting himself (from the wetness and mud of the ground) with a cloak, and the situation was that when he (peace and blessings be upon him) prostrated, there was mud on that cloak."
Abu Ya'la al-Mawsili recorded this hadith in his Musnad. Its chain contains Husayn bin Abdullah bin Ubaydullah bin Abbas, whom the majority of hadith scholars graded da'if (weak); however, the meaning of performing the prayer with care in rainy conditions is also clear from other authentic reports.

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that he saw a man (in prayer) who was prostrating but not bowing, so he (may Allah be pleased with him) said (correcting him): "You have adopted the wrong way; there is no prostration (valid in the Shari'ah) without bowing."
Al-Matalib al-'Aliyah bi-Zawa'id al-Masanid al-Thamaniyah: 508, Musnad Musaddad. Its chain contains Abdullah bin Ziyad bin Sam'an, who is matruk (abandoned); however, the order of the pillars of prayer and the obligation of bowing and prostration are established by other authentic and reliable hadith.

It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that he said: "We used to make supplications while standing and sitting, and to glorify Allah Almighty while bowing and prostrating."
And in the narration of Ahmad bin Mani', Humayd al-Tawil said that Imam al-Hasan al-Basri (may Allah have mercy on him) led us in one of the two late-day prayers (Zuhr or Asr) and made it quite long. I saw (during the prayer) the movement of his blessed beard, so when he had completed the prayer and finished, I asked him: "Were you reciting (in this long standing)?" He replied: "Indeed, most of it consists of glorification and supplication." Then he narrated the above-mentioned hadith by way of Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both).

It is narrated from Sayyidah Aishah (may Allah be pleased with her) that she said: It was my turn with the Messenger of Allah (peace and blessings be upon him). He (peace and blessings be upon him) quietly rose from the bed and went out. I thought that perhaps he (peace and blessings be upon him) had gone to one of his other honoured wives, so, moved by the natural feeling of jealousy, I went out after him (peace and blessings be upon him), and suddenly I saw that he (peace and blessings be upon him) was in prostration, lying still like a garment thrown on the ground. I heard him (peace and blessings be upon him) reciting this supplication: 'Sajada laka sawadi wa khayali, wa amana bika fu'adi, hadhihi yadi wa ma janaytu 'ala nafsi, ya 'Azimu yurja li-kulli 'azim, faghfir al-dhanb al-'azim' (O Allah, my being and my inner self have prostrated before You, and my heart has believed in You; here is my hand before You, and I confess the sin and wrong I have done against myself; O Mighty Lord from whom good is hoped for in every great matter, forgive my great sin). Then the Messenger of Allah (peace and blessings be upon him) raised his blessed head and asked: "What brought you out?" I said: I had formed a suspicion. He (peace and blessings be upon him) said: "Indeed, some suspicion is a sin," as Allah Almighty says: "Indeed, some suspicion is sin" [Surah al-Hujurat: 12], "so seek forgiveness from Allah Almighty. Indeed, Jibril (peace be upon him) came to me and ordered me to say these words which you heard, so you too should recite them in your prostration, for any servant who says these words does not raise his head from prostration until he is forgiven."
Musnad Abi Ya'la: 510. Its chain contains Uthman bin Ata al-Khurasani, a da'if (weak) narrator, and his hearing from his father is not established; however, some parts of the supplication are established in other reliable reports.

It is narrated from Sayyiduna Sa'd bin Abi Waqqas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When the servant prostrates, he prostrates on seven limbs: his face, his two palms, his two knees and his two feet. So as long as he does not do this (that is, does not place all seven limbs on the ground), he has certainly fallen short (in the completeness of his prostration)."
Abu Bakr bin Abi Shaybah and Abd bin Humayd narrated it likewise.
I (Ibn Hajar) say: Muhammad bin Umar al-Waqidi, who is in its chain, is extremely da'if (weak), but he is not alone in transmitting this report; rather, Abu Ya'la also narrated something similar from Abdullah bin Ja'far by way of Muhammad bin Abi al-Wazir. Abdullah bin Ja'far (who is the father of Ali bin al-Madini) is alone in transmitting this report and he is da'if (weak); moreover, he erred in stating its chain, because Amir bin Sa'd actually narrated it from Sayyiduna al-Abbas bin Abd al-Muttalib (may Allah be pleased with him), and that is how Muslim and the authors of the Sunan narrated it with an authentic chain.