From the Rebbe’s explanation:
– Although all the forefathers were the “chariot” of G‑d, Yitzchok was different because unlike Avraham and Ya’akov, he never left Eretz Yisroel: he was a “perfect olah (burnt sacrifice).”
So too with the Maggid (compared to the Baal Shem Tov): Whereas the Baal Shem Tov used to travel extensively, the Maggid, for the entire duration of his leadership, stayed in the one place. Thus both the Maggid and Yitzchok stayed in their places of residence and from there exerted their influence on the entire world.
What does this mean in man’s service to ha-Shem? In serving G‑d, a Jew sometimes must leave his place of residence, and at other times must stay firmly in his place. “Place” in spiritual terms refers to the special defined territory of a Jew — his quintessence, which comes from his soul, “part of G‑d Above.” Every Jew, notwithstanding their differences in terms of their revealed powers, possesses such a “place.”
Laughter and joy
Yitzchok is also associated with Sukkos, the “Season of our Rejoicing.” “Yitzchok” means laughter and joy. Although in future tense, it also refers to laughter in the present and past, for the name was given to commemorate Avraham’s and Sarah’s laughter at the time of Yitzchok’s birth. Moreover, Sarah laughed even before Yitzchok’s birth, when the angels informed her and Avraham that they would have a son.
True, the apex of laughter and joy will be in the future, as stated: “than our mouth will be filled with laughter.” But this joy is not a new thing, but the completion of the laughter in the past and present — as stated, “then our mouths will be filled with laughter,” indicating that even now there is laughter, but not the full amount. Thus the joy of the second night of Sukkos is emphasized by its “guest,” Yitzchok, who also symbolizes joy and laughter.
Obtaining Ruach Hakodesh
The Maggid, too, is associated with Simchas Bais Hashoeva – Celebration of the Water Drawing. Our Sages said: “Why is it called “Bais Hashoeva”? For from there Ruach Hakodesh (Divine Spirit) is drawn.” Because all Jews participated in the Simchas Bais Hashoeva, it follows that all of them drew ruach hakodesh from it. Although the different categories of Jews drew different levels of ruach hakodesh, all of them drew it in some measure. Even, children whose parents took them to the Simchas Bais Hashoeva, drew ruach hakodesh!..
Today’s “guest,” the Maggid, teaches a new insight into this phenomenon. He taught: “Today, in the time of exile, it is easier to obtain ruach hakodesh than in the times of the Bais Hamikdosh. A parable to this is a king to whom, when he is in his palace, it is impossible to approach as closely as when he is on the way, for then anyone who wishes may approach him — even a villager who is not fit to come before the king in his palace; whereas on the way, in his inn, he may come before him and speak with him.”
From the Rebbe’s talk on the 2nd Night of Sukkos, 5744 (1983).