Q. How many Rakaats does a Musaafir complete if he joins a Muqeem Imaam in congregation during the last sitting posture of Salaah?
A. If a traveller (Musaafir) is performing Salaah behind an Imaam who is a non-traveller (Muqeem), a traveller will perform the full Salaah behind the Imaam like a non-traveller.
Similarly, if a traveller joins the Imaam in the last sitting posture of Salaah, a traveller will complete the full Salaah and will not shorten the Salaah i.e. he will complete 4 Rakaats for either Zuhr, Asr and Esha Salaah respectively. (Tahtaawi 1/427 – Khairul Fataawa 2/669)
Allah Ta’ala Knows Best
Mufti Ismaeel Bassa
This answer was collected from TheMufti.com, which is a fatwa portal managed by Mufti Ismaeel Bassa from South Africa.