مَنْ سَقى مُؤْمِناً شَرْبَةً مِنْ مَاءٍ مِنْ حَيْثُ يَقْدِرُ عَلَى الْمَاءِ، أَعْطَاهُ اللَّهُ بِكُلِ شَرْبَةٍ سَبْعِينَ أَلْفَ حَسَنَةٍ، وَ إِنْ سَقَاهُ مِنْ حَيْثُ لَايَقْدِرُ عَلَى الْمَاءِ، فَكَأَنَّمَا أَعْتَقَ عَشْرَ رِقَابٍ مِنْ وُلْدِ إِسْمَاعِيلَ.
The Prophet Muhammad (S):
Whoever quenches a believer's thirst with a drink of water when water is easily available, for every drink of water, Allah will give him seventy thousand rewards. And if he quenches his thirst when water is not easily accessible, it is as if he has set free ten slaves from the children of Ishmael.
Source:
al-Kāfī
Vol3
P514
ID: 17099