From Sahih Muslim (Hadith 2571):
Anas (Allah be pleased with him) reported that the Messenger of Allah (ﷺ) observed Saum Wisal during the early part of the month of Ramadan. The people among Muslims also observed uninterrupted fast. This (news) reached him (the Holy Prophet) and he said:Had the month been lengthened for me I would have continued observing Saum Wisal, so that those who act with forced hardness would (have been obliged) to abandon it. You are not like me (or he said): I am not like you. I continue to do so (in a state) that my Lord feeds me and provides me drink
Reference: Muslim 2571