‘Ata’ said, “If one rinses his mouth and ejects the water in it, swallowing his saliva and anything that remains in it does him no harm; but one should not chew gum, for although I do not say that he breaks his fast [if] he swallows the saliva produced by the gum, he is nevertheless prohibited from doing it.” Bukhari transmitted it in a chapter heading.
Hadith Referenceمشكوة المصابيح / كتاب الصوم / 2018
Hadith Gradingالألبانی:لم تتمّ دراسته | زبیر علی زئی:صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «رواه البخاري (الصوم باب: 28 بعد ح 1934)»