Musannaf Ibn Abi Shaybah

Hazrat Abu Musa narrates that once we were traveling by sea, and we had raised our sails. We could not see any island, nor could we see anything else. Suddenly, we heard a voice: "O people of the boat! Stop, I will tell you something." We stood up and started looking, but we could not see anything. That caller called out seven times. On the seventh time, I stood up and said, "Whoever you are, tell us what you want to say, you can see our condition and know that we cannot come to you." He said, "I want to inform you of a decree of Allah Almighty which He has made obligatory upon Himself! It is this: Whoever keeps himself thirsty for Allah on a hot day, Allah Almighty will quench his thirst on the Day of Resurrection." Abu Usama says that after this, you could never see Hazrat Abu Musa without fasting.