The Messenger of Allah ﷺ said, "For every group devoted to a particular deed, there is a gate among the gates of Paradise through which they will be called by that deed. The people of fasting have a gate called ar-Rayyan through which they will be called."Abu Bakr asked, "Messenger of Allah, will anyone be called from all of those gates?"He replied, "Yes, and I hope you will be among them, Abu Bakr."
حدثنا يزيد قال أخبرنا محمد بن عمرو عن الزهري عن حميد بن عبد الرحمن
قال رسول الله ﷺ لكل أهل عمل باب من أبواب الجنة يدعون بذلك العمل ولأهل الصيام باب يدعون منه يقال له الريان فقال أبو بكر يا رسول الله هل أحد يدعى من تلك الأبواب كلها قال نعم وأنا أرجو أن تكون منهم يا أبا بكر
Its chain of transmission is sahih. Haythami said in 10/398, "Its narrators are the narrators of the Sahih." It is found in Bukhari 3/32, in the Book of Fasting, "Rayyan for those who fast," and in Muslim 2/808, no. 1152, and in Tirmidhi 3/128, no. 765.