Reference : Hisn al-Muslim 176

ذَهَـبَ الظَّمَـأُ،
وَابْتَلَّـتِ العُـروق،
وَثَبَـتَ الأجْـرُ إِنْ شـاءَ الله
Dhahabaẓ-ẓama', 
wabtallati ‘l-`urūq, 
wa thabata ‘l-'ajru in shā Allāh.


The thirst is gone,
the veins are moistened, 
and the reward is confirmed, if Allah wills.

Reference:
Abu Dawud 2/306 and others. See also Al- Albani, Sahihul-Jami' As-Saghir 
4/209.

Chapter: Upon breaking fast