The Messenger of Allah ﷺ said, "Whoever breaks his fast for a single day in Ramadan without a valid concession or illness, fasting the rest of his life will not make up for it, even if he were to do so."
حدثنا محمد بن بشار حدثنا يحيى بن سعيد وعبد الرحمن بن مهدي قالا حدثنا سفيان عن حبيب بن أبي ثابت حدثنا أبو المطوس عن أبيه
قال رسول الله ﷺ من أفطر يوما من رمضان من غير رخصة ولا مرض لم يقض عنه صوم الدهر كله وإن صامه
[Its chain is daif] It was also related by Abu Dawud in the Book of Fasting, chapter on the severe warning against one who breaks the fast deliberately, hadith 2396, from the hadith of Habib, and in it is Abul-Mutawwis, who is lenient in transmission, and his father is unknown (Taqrib). Ibn Khuzayma criticized it as defective, hadith 1987.