Q. An Imaam recited a verse of Surah Faatihah twice in Salaah mistakenly. Is the Salaah valid?
A. In principle, to repeat a verse of Surah Faatihah in Salaah mistakenly or intentionally does not render the Salaah invalid.
However, to repeat a major portion (more than half) of Surah Faatihah in Salaah mistakenly will necessitate the performance of a Sajdah Sahw to compensate for it. By doing so intentionally, a Sajdah Sahw will not suffice and the repetition of the Salaah will be necessary.
Nevertheless, in the enquired case, the Salaah of the Imaam and the congregation remains valid. (Al Barur-Raaiq 2/101)
Allah Ta’ala Knows Best
Mufti Ismaeel Bassa