Kabbalah zu Bereschit 22:9

And on that day Yitzchak crowned himself and he is the head of the Patriarchs. About that day it is written "In Tzion the sinners feared" (Isaiah 33:14). On that day Yitzchak bounded himself up, and everything was bound up, and Sarah wailed [diff. version: broke down], and the voice of the shofar was very strong. Happy is the lot of the one who passes through them and is saved from them. Rabbi Aba said: because of this we read the parashah of the Binding of Yitzchak on this day, because on this day Yitzchak bound himself up with the lower, and [so] connected/knotted himself with the One Above [diff. version: with Avraham]. When did he bound himself up?At the time when it is written "and he bound his son Yitzchak up" (Genesis 22:9).