The Seudah That Is Like a Fast

Sefer Likutei Yehuda quotes his grandfather, the Chiddushei Harim zy”a, as saying that when groups of chasidim get together for a seudah, it is considered to be like a tainis. He explains that the main purpose of a tainis is for Yidden to get together to inspect their ways and see how they can improve and atone for their past sins (see Tainis 12A). Unfortunately, the main purpose of fast days often became forgotten and they simply became days when people didn’t eat, rather than days used for teshuva.

Therefore, the chasidim decided that instead of fasting they would gather for joint seudos, when they would instill each other with yiras shomayim and help each other rectify their ways.