كتاب الفضائل
9
The Book of Virtues
Abu Hurairah (May Allah be pleased with him)reported:
The Prophet (ﷺ) said, "The five daily (prescribed) Salat, and Friday (prayer) to the next Friday (prayer), and the fasting of Ramadan to the next Ramadan, is expiation of the sins committed in between them, so long as major sins are avoided."

[Muslim].

وعنه عن النبي، صلى الله عليه وسلم قال‏:‏ ‏ "‏الصلوات الخمس والجمعة إلى الجمعة، ورمضان إلى رمضان، مكفرات ما بينهن إذا اجتنبت الكبائر‏"‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏
Sunnah.com reference : Book 9, Hadith 159
Arabic/English book reference : Book 9, Hadith 1149