What is the ruling on repeating a verse from Al-Fatihah more than once during prayer?

Repeating Al-Fatihah or a verse from it does not invalidate the prayer, even if done intentionally, but it is disliked according to the Hanbalis. As for the Shafi'is, there is no harm in repeating it, whether due to doubt or otherwise, and the continuity is not broken by that. What is relied upon by the Malikis is that intentionally repeating Al-Fatihah does not invalidate the prayer. In case of forgetfulness, a prostration of forgetfulness (sujud al-sahw) is performed after the salam for repeating the entire Al-Fatihah, but not for repeating a single verse.