What are the hadiths that mention the merits of tasbih and istighfar?

We do not know of the two invocations (dhikrain) appearing in their exact form in a single hadith. However, the Messenger of Allah (peace and blessings be upon him) frequently said: "Subhan Allah wa bihamdihi, astaghfirullah wa atubu ilayh" (Glory be to Allah and with His praise, I seek forgiveness from Allah and repent to Him). Aisha (may Allah be pleased with her) said that he informed her that he had seen a sign in his nation, which was "If Allah's help and victory come," referring to the conquest of Mecca, "and you see people entering Allah's religion in crowds." It was also reported from him (peace and blessings be upon him) that "Two phrases are beloved to the Most Merciful, light on the tongue, and heavy on the scale: Subhan Allah wa bihamdihi, Subhan Allah al-Adhim" (Glory be to Allah and with His praise, Glory be to Allah the Almighty). He also used to say: "O people: Repent to Allah and seek His forgiveness, for I repent one hundred times a day." It was narrated from Ibn Umar that he was with the Prophet (peace and blessings be upon him) and said: "Allahumma ighfir li wa tub alayya, innaka antat-Tawwabur-Rahim" (O Allah, forgive me and accept my repentance, for indeed You are the Acceptor of Repentance, the Most Merciful) one hundred times.