Q. In certain countries like Mexico it is customary to greet a friend eating a meal with Buen Provecho, similar to Bon Apetite in french or Beteavon in Hebrew. One encountering friends eating and not greeting them as mentioned, could be considered as an offense.
If the one eating is an ill person who is allowed to eat on a fast day such as Shiva Assar Betamuz, can he be greeted?
A. Horav Shlomo Miller’s Shlit’a opinion is that is is permitted on Shiva Assar Betamuz and similar lesser fast days but not on Tisha Beav since as is, greeting are avoided. One should explain, as is done with other greetings, why it is not proper.
On Yom Kippur, the Day of Atonement, it is definitely not correct to great one in that way. One should simply wish a Refuah Shleimah to the patient.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a