The Messenger of Allah ﷺ said, "Whoever breaks his fast for a single day of Ramadan without an allowance granted to him by Allah, fasting the rest of his life will not make up for it."
حدثنا بهز قال حدثنا شعبة قال أخبرني حبيب بن أبي ثابت قال سمعت عمارة بن عمير عن أبي المطوس عن أبيه
قال رسول الله ﷺ من أفطر يوما من رمضان في غير رخصة رخصها الله له فلن يقبل منه الدهر كله
Its chain of transmission is daif because of Abul-Mattawwas. It will come with a sahih chain of transmission at 6796, 9870, and 10036. Some scholars considered Abul-Mattawwas daif, while others considered him unknown. His narration appears in Tirmidhi 3/92, number 723, in the chapter on fasting, on what has been said about breaking the fast deliberately, where Tirmidhi noted its unusualness. It also appears in Abu Dawud, as a suspended narration, 2/160.