Kabbalah zu Schemot 13:22

Rabbi Shimeon said: "pillar of cloud during the day" (Ex. 13:22): this is Avraham (chesed). "And pillar of fire during the night": this is Itzchak (gevurah). And both of them are found in the Shechinah, and what Rabbi Abba said (yesod) is certainly obvious, that on through this, at this level, they are found.