Imam Al-Nawawi's Riyad-us-Saliheen
Book Sixteen: The Book of Du'a (Supplications)
Chapter 250 :
Issues regarding Supplications, their Virtues and Supplications of the Prophet (sallallaahu ’alayhi wa sallam)
Chapter 251 :
The Excellence of Supplicating in one's Absence
Chapter 252 :
Some Verdicts Pertaining to Supplications
Chapter 253 :
Superiority of Auliya' and their Marvels