Umar bin al-khattab reported the Messenger of Allah ﷺ as saying; When the MuadhDHIN says: “Allah is most great, Allah is most great”, and one of you says in response: “Allah is most great”, Allah is most great; then says: “ I testify tht there is no god but Allah”, and he says in response: “I testify that there is no god but Allah”, then say: ” I testify that Muhammad is the Messenger of Allah”, and he makes the response: “ I testify that Muhammad is the Messenger of Allah”, then says: “Come to prayer”, and he makes the response: “There is no might and no power except in Allah”: then says: “ Allah is most great, Allah is most great”, and he makes the response: “Allah is most great”, then says: “There is no god but Allah”, if he says this from his heart, he enter Paradise.
Hadith Referenceسنن ابي داود / كتاب الصلاة / 527
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم (385)
Narrated Umar: The Prophet ﷺ as saying: When the night approaches from this side and the day retreats on that side, and the sun sets - according to the version of Musaddad - he who fasts has reached the time to break it.
Hadith Referenceسنن ابي داود / كتاب الصيام / 2351
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح بخاري (1954) صحيح مسلم (1100)