Fortress of the Muslim (Hisn al-Muslim)
حصن المسلم
(87) Chapter: To one who does you a favour
(87) الدعاء لمن صنع إليك معروفاً
Hisn al-Muslim 198 
Jazākallāhu khayra. May Allah reward you with good. Reference: At-Tirmidhi (no. 2035). See also Al-Albani, Sahih At-Tirmidhi 2/200 and Sahihul-Jami' (no. 6244).
جَزاكَ اللهُ خَـيْراً
Reference : Hisn al-Muslim 198