الكافي- ط الاسلامية, volume 3, page 357

6. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from Ali ibn al-Nu‘man from Sa‘id al-‘A’raj who has said the following: “I heard abu ‘Abd Allah (a.s.), say, ‘The Messenger of Allah once said Salam (the phrase of offering greeting of peace) in two Rak‘at and those behind him asked, “O Messenger of Allah, has something happened to Salah (prayer)?” The Messenger of Allah asked, “Why is that?” They replied, “You performed only two Rak‘at.” The Messenger of Allah then asked, “Was it so, O Dhu al- Yadayn?” - he was also called Dhu al-Shamalayn - He replied, “Yes, it was so.” The Messenger of Allah based his Salah (prayer) on that and completed it as four Rak‘at.’ He (the Imam) said, ‘Allah made him to forget to grant and make it a mercy for the nation (his followers). Is it not true that if a man does so, he is reproached and is told that his Salah (prayer) is not accepted? If today someone experiences such condition he says that the Messenger of Allah has established a Sunnah (tradition) and it has become a guideline to follow. He (the Messenger of Allah) then performed two Sajdah (prostration) because of speaking.’”

Translation: Muhammad Sarwar — attributed by Thaqalayn·The Arabic above is the original.

7. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from al-Husayn ibn Sa‘id from al-Qasim ibn Muhammad from Ali ibn abu Hamzah who has said the following: “Abu ‘Abd Allah (a.s.), has said, ‘If you stand up in the first two Rak‘at without saying Tashahhud (testimonies of belief), then remember before Ruku‘ (bowing down on one’s knees), you must sit down. You must say Tashahhud (testimonies of belief). In case, if you do not remember until Ruku‘, then continue your Salah (prayer) as you are. When you end, perform two Sajdah (prostration) without Ruku‘, then say Tashahhud (testimonies of belief) which you had missed.’”

Translation: Muhammad Sarwar — attributed by Thaqalayn·The Arabic above is the original.

8. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from Hammad ibn ‘Uthman from al-Halabiy who has said the following: “Abu ‘Abd Allah (a.s.) has stated this Hadith. He (the Imam) has said, ‘You may stand up in the two Rak‘at of al-Dhuhr or others without saying Tashahhud (testimonies of belief) and remember it in the third Rak‘at before Ruku‘ (bowing down on one’s knees), you must sit down, then say Tashahhud (testimonies of belief), then stand up and complete your Salah (prayer). In case, if you do not remember until Ruku‘, then continue your Salah (prayer) until the end. When you complete it, then perform two Sajdah (prostration) because of mistake after Salam (the phrase of offering greeting of peace) and before speaking.’”

Translation: Muhammad Sarwar — attributed by Thaqalayn·The Arabic above is the original.

9. Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa from Yunus from Mu‘awiyah ibn ‘Ammar who has said the following: “I once asked him (the Imam) (a.s.), about a man who mistakenly stands up where he was to sit or sits down where he was to stand up. He (the Imam) said, ‘He performs two Sajdah (prostration) after Salam (the phrase of offering greeting of peace) which are destroyers to destroy Satan.’”

Translation: Muhammad Sarwar — attributed by Thaqalayn·The Arabic above is the original.