Is Witr performed before the Isha prayer valid?
Chapter on the Times When Prayer is Prohibited
Al-Mughni
Book of Prayer
Primary text
Witr performed before the Isha prayer is not valid (it does not count). This is reasoned by analogy, as performing it before its established time is similar to praying a voluntary prayer during the daytime.
Supporting text
Al-Thawri and Abu Hanifa held that if one prays Witr before Isha out of forgetfulness, one is not required to repeat it. However, their two companions disagreed, stating that it must be repeated. Malik and Al-Shafi'i concur that it must be repeated.