A hadith like this has been reported from the Messenger of Allah (ﷺ) by 'Abd al-Malik with the same chain of transmitters in connection with fast.
Sahih Muslim Book 13, Hadith 263
← Previous Hadith Prayer offered in the middle of the night and the most excellent fast after (fasting) in the month of Ramadan is the fast in God's month al-Muharram.

Sahih Muslim Book 13, Hadith 262 Next Hadith → He who observed the fast of Ramadan and then followed it with six (fasts) of Shawwal. it would be as if he fasted perpetually.

Sahih Muslim Book 13, Hadith 264