Fiqh-us-Sunnah Volume 2, Supererogatory Prayer, Fiqh 2.001.
Section : Their Significance, Supererogatory Prayers. At-tatawwu’, or nawafil or supererogatory prayers, have been legislated to make up for any deficiencies left in the performance of fard salah (obligatory prayers). In salah, there are virtues that are not found in…