Is it permissible for a woman to pray without covering her hands, and is there any evidence for that?

The majority of jurists hold the view that the palms of the hands are not 'awrah (parts of the body that must be covered) during prayer, basing their argument on the Almighty's saying: ﴿And not expose their adornment except that which [necessarily] appears thereof﴾ [An-Nur: 31]. Ibn 'Abbas and others interpreted "that which appears thereof" as the face and the palms of the hands, and that they are not 'awrah due to the necessity of exposing them. As for the Hanbalis, they held the view in one of two narrations that they are 'awrah during prayer, basing their argument on the hadith (definition): "The woman is 'awrah." There is a distinction between the 'awrah for prayer and the 'awrah for looking.