Tuesday Nissan 22, Acharon Shel Pesach 5703, 7th day of the Omer
Chumash: Acharei mot, Shlishi with Rashi.
Tehillim: 106-107.
Tanya: And although He (p. 221)...above in ch. 20. (p. 223).
By day we take care to follow this order:
Make Kiddush, then Daven Mincha, and after that eat the Festive Yom Tov meal. [1]
The Baal Shem Tov used to eat three festival meals on Acharon Shel Pesach.
The Baal Shem Tov called the (third) meal of this day Mashiach's S'uda (the "festival meal of Mashiach").
Acharon Shel Pesach is the day for Mashiach's S'uda because on this day the radiance of the light of Mashiach shines openly.
In 5666 (1906) a new procedure was adopted for Pesach in the Yeshiva Tomchei T'mimim in Lubavitch: The students ate the Pesach meals all together, in the study hall. There were 310 [2] students present seated at eighteen tables. My father the Rebbe ate the festive meal of Acharon Shel Pesach with the yeshiva students. He ordered that four cups of wine [3] be given each student, and then declared, "this is Mashiach's S'uda."
Notes:
A parallel to the three Shabbat meals, in contrast to the two festival meals.
The number 310, Shai, has a significance, the number of "worlds" awaiting each Tzadik. or chai represents life.
The Rebbe Sh'lita stated, that "it is obvious that this practice was not to be limited to that particular year, but is for all years."