Ambrose of Milan

Therefore, the just man commends his vow with swiftness. And our fathers hastened to eat the Passover, having their loins girded, and their feet shod with shoes, and carrying burdens of the body, so that they would be ready for the passage; for the Passover of the Lord is a passage from sufferings to exercises of virtue. And therefore it is called the Passover of the Lord; because even then in that Lamb the truth of the Lord's Passion was announced, and now it is celebrated by his grace.

On Cain and Abel 1.8.31 ↗

Gregory the Dialogist

Since therefore we have learned how the Passover ought to be eaten, let us now recognize by whom it ought to be eaten. It follows: "And thus shall you eat it. You shall gird your loins." What is understood by the loins except the delight of the flesh? Hence the Psalmist also asks, saying: "Burn my loins." For if he had not known that the pleasure of lust resides in the loins, he would by no means have asked that they be burned. …

Forty Gospel Homilies, Homily 22 ↗

Bede

Passover means "passing over." It derives its ancient name from the Lord's passing over on this [day] through Egypt, striking the firstborn of the Egyptians and freeing the children of Israel, and from the children of Israel's passing over on that night from their slavery in Egypt in order that they might come to the land which had once been promised to their heirs as a land of peace. Mystically it signifies that on this [day] our Lord would pass over from this world to his Father. …

Homilies on the Gospels 2.5 ↗