"When those who fast for Allah in the heat are patient..."
(By Ibn Rajab al-Hanbali)
"Abu ad-Darda' would say: "
Fast the very hot days in anticipation of the Day of Resurrection, and pray two rak'at in the darkness of night in anticipation of the darkness of the grave." And it's reported in the two 'Sahih's that he said: "
You have seen us with the Messenger of Allah (saw) on some of his journeys on very hot days, and a man would hold his hand against his head due to the intensity of the heat, and none of them would be fasting except the Messenger of Allah and 'Abdullah bin Rawahah." And the narration of Muslim states that Abu ad-Darda' said: "
This was during the month of Ramadan."
When those who fast for Allah in the heat are patient despite their intense thirst, He set aside a specific gate of the gates of Paradise for them. This is the gate called Rayyan, and whoever enters through it will drink, and whoever drinks after entering it will never be thirsty again. When they enter through it, it will be locked for those after them, and none will enter through it except them..