Is it permissible to wear a ring on the thumb and the index finger?

A woman may wear a ring on any finger of her hands or feet, because it is an adornment for her. As for a man, the Sunnah is for him to wear a ring on the little finger of his left hand. It is not permissible for him to wear a ring on the index finger or the middle finger. There is a difference of opinion regarding wearing it on the thumb.