Source:
Fatawa of the Scholars of Hadith, Kitāb al-Ṣalāh, Vol. 1, p. 147
Question
If the Tarāwīḥ prayer has already begun and a person arrives who has not yet performed the obligatory ʿIsha’ prayer, may he join the Tarāwīḥ, or must he first perform the ʿIsha’ fard?
Answer
Both of the following options are permissible:
① Performing ʿIsha’ First
✔ If he leaves the Tarāwīḥ and first performs the obligatory ʿIsha’ prayer separately, this is valid, because the congregation at that time is for the nafl (Tarāwīḥ), and there is no prohibition against praying the fard on its own.
② Joining Tarāwīḥ and Making Up ʿIsha’ During the Break
✔ He may join the Tarāwīḥ prayer, and when the Imām pauses after every four rakʿahs, he may perform his missed ʿIsha’ fard during that interval.
(Source: Ahl al-Ḥadīth Suhadrā, Vol. 5, Issue 48)
