Sunan Ibn Majah Book 5, Hadith 96
“When praying at night
(Qiyamul-Lail), the Messenger of Allah (ﷺ) used to say between the
two prostrations: ‘Rabbighfir li warhamni wajburni warzuqni
warfa’ni
(O Lord, forgive me, have mercy on me, improve my
situation, grant me
provision and raise me in status).’”
“Rabbighfir li, Rabbighfir li (O Lord forgive me, O Lord forgive me).”
“When we performed prayer with the Prophet (ﷺ) we said: ‘Peace be upon Allah from His slaves, peace be upon Jibra’il and Mika’il and so-and-so and so-and- so.’ The Messenger of Allah (ﷺ) heard us and said: ‘Do not say peace (Salam) be upon Allah, for He is As-Salam. When you sit (during prayer) say: At-Tahiyyatu lillahi was-salawatu wat-tayyibatu; as- salamu ‘alayka ayyuhan-Nabiyyu wa rahmatullahi wa barakatuhu; as- salamu ‘alayna wa ‘ala ‘ibadillahis-salihin (All compliments, prayers and good words are due to Allah; peace be upon you, O Prophet, and the mercy of Allah and His blessings; peace be upon us and upon the righteous slaves of Allah).” For as you say that it will reach every righteous slave in the heavens and on earth. (Then say:) “Ashhadu an la ilaha illallah wa ashhadu anna Muhammadan ‘abduhu wa Rasuluhu (I bear witness that none has the right to be worshipped but Allah, and I bear witness that Muhammad is His slave and Messenger).”
(Another chain) with similar wording.
(Another chain) that `Abdullah bin Mas`ud said: "The Prophet (ﷺ) used to teach us the Tashahhud." And he mentioned similarly.