Full Sharh — Riyad as-Salihin 418

English Translation

Umm Habibah (May Allah be pleased with her) the Mother of the Believers reported:: I heard the Messenger of Allah (ﷺ) saying, "A house will be built in Jannah for every Muslim who offers twelve Rak'ah of optional Salat other than the obligatory Salat in a day and a night (to seek the Pleasure of Allah).".