1217 — Sahl ibn Saʿd reported that the Prophet ﷺ said: “In Paradise there is a gate called al-Rayyān. Those who observed the fast will enter through it on the Day of Resurrection, and none but they will enter it. It will be announced, ‘Where are the people of fasting?’ They will stand, and none but they will pass through. Once they have entered, the gate will be shut, and no one else will enter by it.” Agreed upon.

1218 — Abu Saʿid al-Khudri reported that the Messenger of Allah ﷺ said: “No servant fasts a single day for the sake of Allah but that, by that day, Allah distances his face from the Fire by seventy years.” Agreed upon.

1219 — Abu Hurayra reported that the Prophet ﷺ said: “Whoever fasts Ramadan out of faith and seeking reward will have his past sins forgiven.” Agreed upon.

[Commentary]
These hadiths that al-Nawawi cites in Riyad al-Salihin all testify to the virtue of fasting. Among them is the report of Abu Hurayra, may Allah be pleased with him, in which the Prophet ﷺ said: “Whoever spends a pair of something in the cause of Allah will be called from the gates of Paradise: ‘Servant of Allah, this is good!’”