וַיְהִ֕י בְּעֶ֖צֶם הַיּ֣וֹם הַזֶּ֑ה הוֹצִ֨יא יְהוָ֜ה אֶת־בְּנֵ֧י יִשְׂרָאֵ֛ל מֵאֶ֥רֶץ מִצְרַ֖יִם עַל־צִבְאֹתָֽם׃ (פ)
And it came to pass the selfsame day that the LORD did bring the children of Israel out of the land of Egypt by their hosts.
Read kabbalistic (mystical) interpretation of Exodus 12:51: and classical mystical sources.