It wasnarrated from Abu Hurairah that the Messenger of Allah (ﷺ)said:
"Whoever does not fast one day in Ramadan without having aconcession allowing that, fasting for a lifetime will not make up forthat." (RU)
English reference (RU): Vol. 1, Book 7, Hadith 1672 (RU)
Arabic reference (RU): Book 7, Hadith 1742 (RU)