Bo: Rabbeinu Bachya: Making It Tangible: Mitzvah 10 – Concept 115
“And you shall tell your son on that day, saying, ‘It is because of this that God acted on my behalf when I left Egypt.” (Exodus 13:8) We are commanded to relate the story of the Exodus from Egypt on the night of Pesach. (Rambam, Hilchot Chametz U’Matzah)
This verse tells us that the fact that I was able to leave Egypt was all for the sake of His glory and His Name.
It is somewhat similar to what Moshe and Israel exclaimed after crossing the sea, “This is My Lord, and I will glorify Him,” a complimentary reference to the Divine Presence.
The meaning is that the Divine Presence in Israel is not merely something needed for the ordinary Israelite, but it is a phenomenon necessary even in celestial circles. This is what Joshua had in mind when he said, “And what are You going to do in order to bolster Your great name?” (Joshua 7:9 – after the Israelites defeat at Ai.)
When the Torah immediately continues in the next verse by writing, “This shall be a sign on your hand and a remembrance between your eyes,” the idea is that the concept the Torah has revealed to us here must be commemorated by us in a tangible form. (Rabbeinu Bachya)