TB Khullin 105 How long do you have to wait between eating milk and meat?

Today’s daf TB Khullin 105 discusses how long do you have to wait between eating milk and meat and meat and milk.

“Rav Asi posed a dilemma to Rabbi Yoḥanan: How much time should one wait between eating meat and eating cheese? Rabbi Yoḥanan said to him: No time at all. The Gemara asks: Is that so? But doesn’t Rav Ḥisda say: If one ate meat, it is prohibited for him to eat cheese immediately, but if he ate cheese it is permitted for him to eat meat without delay? Rather, Rav Asi actually asked Rabbi Yoḥanan the following question: How much time should one wait between eating cheese and eating meat? In response to this question, Rabbi Yoḥanan said to him: No time at all.

“After tangentially citing a statement of Rav Ḥisda, the Gemara discusses the matter itself. Rav Ḥisda says: If one ate meat, it is prohibited for him to eat cheese immediately, as the meat contains fatty substances that stick to one’s mouth and preserve the flavor of meat. But if he ate cheese it is permitted for him to eat meat without delay. Rav Aḥa bar Yosef said to Rav Ḥisda: In the case of meat that is between the teeth, what is the halakha? Are these remnants considered meat to the extent that one may not eat cheese as long as they are in his mouth? "In response, Rav Ḥisda read about him the following verse: “While the meat was yet between their teeth” (Numbers 11:33). This verse indicates that even when the meat is between one’s teeth it is still considered meat, and therefore one may not partake of cheese until that meat has been removed.” (Sefaria.org translation)

Even though one does not have to wait between eating milk then meat, the Gemara teaches that one should clean the mouth by wiping it with some solid food and then rinsing it in order to remove all dairy residue. Today that would mean brushing your teeth and rinsing them. Because during this time period utensils like forks and spoons did not exist or were hardly used and most foods were eaten by hand, there’s also a tradition of washing your hands after eating cheese so no cheese residue remains on your hands before you eat your meat.

Since the Gemara is ambiguous concerning how much time one must wait between eating meat and milk, many different traditions arose. One is forbidden to eat cheese after eating meat, fowl, and undomesticated kosher animals until one has waited six hours which is the measurement of time that one waits between meals. However even after waiting six hours there still meat between one’s teeth, one must remove the meat from his teeth. There are those who say one does not have to wait six hours. As long as one stops eating meat and recites Grace after meals, one is permitted eat the cheese after wiping and rinsing the mouth. There are those who have the tradition of waiting only one hour between eating meat and milk. Nevertheless without reciting Grace after meals, waiting one hour is insufficient. After one hour one still finds meat stuck between his teeth, he has to remove it. Those who are scrupulous wait six hours after eating meat before eating cheese. See Rambam, Mishneh Torah, Forbidden Foods, Chapter 9 Halakha 28 and Shulkhan Arukh, Yoreh De’ah 89:1.

I don’t know where the tradition awaiting three or four hours between eating meat and milk originated even though many people observe this tradition as well.