Theodoret of Cyrus

Why did God command Moses to erect the tabernacle on the first day of the first month? Because at that time he created the world. The sprouting of the trees attests to this fact. For Scripture says, “Let the earth sprout forth grass for fodder, and sow seed according to its kind and its likeness, and fruit-bearing trees that produce fruit, with its seed within it in its likeness, according to its kind upon the earth.” When spring begins, the meadows bloom, the fields grow like waves, and the trees germinate their fruit. So too in this very season God set Israel free from slavery under the Egyptians and the archangel Gabriel brought the holy virgin the good news of her mysterious childbearing. In this same season the Lord Christ underwent his saving passion. Most fittingly, the Lord God of all ordered the tabernacle to be erected on the first day of the first month because it was the image of the entire world, and also so that the people would prepare for the feast of Passover, which the law commanded the Jews to celebrate as the first feast. At that time, they were going to celebrate this feast for the first time in the desert, for this was the second year after their deliverance from slavery.