Abraham called the name of his son . . . Yitzchak.”

-Vayeira 21:3

The Talmud (Shabbat 89b) states that in the Messianic age it is specifically of Yitzchak (Isaac) that we shall say “for you are our father” (Isaiah 63:16). Chassidut explains that the name Yitzchak is an expression of laughter and delight: in the Messianic age, the supernal joy and delight caused by our present service of G‑d will be revealed.

Chassidut explains further that the patriarch Isaac represents the aspect of fear and awe of G‑d, and the consequent self-negation before G‑d. It is, therefore, specifically Isaac who relates to the future era, for at that time G‑dliness will manifest itself in the world, and all creatures will be moved to a sense of self-negation.

Indeed, Isaac’s life reflected certain qualities of the Messianic era. The Zohar (I: 60a) notes: when Abraham was about to sacrifice his son (Vayeira ch. 22), Isaac’s soul departed from his body and was replaced by a soul from the “world to come.” By virtue of this new soul, related to the era of redemption, Isaac’s life was in the mode of the future era of the redemption.