As we have seen (Peninei Halakha: Mo’adim 1:11), the Torah commands us to include the poor and lonely in the festivities and to invite them to share our meals, as we read, “You shall rejoice in your festival, with your son and daughter, your male and female slave, the Levite, the stranger, the fatherless, and the widow in your communities” (Devarim 16:14). These are the guests (ushpizin) whom it is a mitzva to invite into the sukka. According to Zohar, it is also appropriate to invite “supernal guests” (“ushpizin ila’in”) into the sukka. These are the souls of seven righteous people, Avraham, Yitzḥak, Yaakov, Yosef, Moshe, Aharon, and David, whose light shines on Sukkot. On each day of the festival, the light of one of them shines brightest, and he enters the sukka first, accompanied by the other six.
Zohar on Parashat Emor tells of the practice of R. Hamnuna Saba. Entering the sukka made him happy, so he would stand in its doorway and say: “Sit down, supernal guests, sit down. Sit down, guests of faith, sit down.” He would then joyously raise his hands and exclaim: “Happy is our lot, happy is the lot of Israel, who sits in the sukka!” For everyone who has a share in the holy nation and the holy land is sitting in the shelter of faith and receiving the light of the seven righteous visitors. He will rejoice in this world and the next.
Nevertheless, one must make sure to bring joy to the poor, since the share of the seven righteous whom he invited to the sukka belongs to them. If one sits in the shelter of faith and invites supernal guests of faith but does not give their share to the poor, these righteous guests get up to leave. They are not interested in being hosted by a miser, as Scripture states: “Do not eat of a stingy man’s food; do not crave his dainties” (Mishlei 23:6-7). The table he set for the meal is his own table, not God’s table, and of him it is written: “I will strew dung upon your faces, the dung of your festival sacrifices” (Malakhi 2:3). Woe to this host when the supernal guests desert his table. When our patriarch Avraham – who spent his whole life standing at the crossroads inviting guests and setting the table for them – sees that this person has set his table without including the poor, he gets up and announces, “Move away from the tents of these wicked men” (Bamidbar 16:26). All the rest of the supernal guests then file out after him. On their way out, Yitzḥak says, “The belly of the wicked will be empty” (Mishlei 13:25), and Yaakov says, “The morsel you eat you will vomit” (ibid. 23:8). The rest of the righteous say, “For all tables are covered with vomit and filth without the Omnipresent” (Yeshayahu 28:8).
Zohar further states that one should not say, “First I will eat and drink to satiety, and then I will give what is left to the poor.” Rather, he should first give to the poor. If he acts properly, bringing joy to the poor and filling them to satiety, God delights in him. Avraham says of him, “Then you can seek the favor of the Lord. I will set you astride the heights of the earth” (Yeshayahu 58:14), and the rest of the righteous apply various positive verses to him. Happy is the person who merits this (Zohar III 103b-104a).
We must add that if someone gives charity to the poor before the festival in accordance with his means, he is also fulfilling the mitzva by making sure that they are included in the festival joy. Nevertheless, hosting them in his sukka is a greater mitzva. Nowadays it is particularly important to make a point of inviting people, as there are very few people today who are actually starving, but there are many people who are sad and lonely. It is a great mitzva to make efforts to invite them to join in the celebration.
Many siddurim include a formula for inviting the ushpizin ila’in each day. The traditional order is: Avraham, Yitzḥak, Yaakov, Moshe, Aharon, Yosef, David. This is the custom of Sephardim and Ḥasidim (Kaf Ha-ḥayim 639:8). In Ashkenazic custom, the order is Avraham, Yitzḥak, Yaakov, Yosef, Moshe, Aharon, David (Siddur Ha-Shlah). Some people make a point of having Torah discussions each day about that day’s guest. Some people, who share a name with one of the ushpizin, make a party in their sukka on the night of “their” supernal guest, setting out refreshments and wine for their human guests, and inviting Torah scholars to speak.