Slaves Of Satan

Affligit Pharao filios Israel luto et latere. Israel similitudo est populi nostri. Pharao autem est diaboli, qui imposuit jugum gravissimum servitutis ex luto et latere operari; id est, terrenis et lutulentis operibus incubare, admistis etiam paleis, hoc est, levibus et irrationabilibus factis, ut his vitiroum actibus populum Dei comprimere, et pectora omnium muro incredulitatis posset occludere, ut nemo esset, qui regnum ejus aut disperderet, aut vinceret. Sanctus Isidorus Hispalensis,Mysticorum Expositiones Sacramentorum Seu Quaestiones In Vetus Testamentum, In Exodum, Caput III Source: Migne PL 83.287a-b

The Pharaoh afflicts the sons of Israel with mud and bricks. Israel is a figure for our people, Pharaoh of the devil, he who imposes a heavy yoke of servitude with the labour of mud and bricks, that is, he oppresses with worldly and defiling work, sending us even to straw, that is, fatuous and irrational deeds, that with these deeds of vice he oppress the people of God and enclose their hearts within a wall of disbelief, that there be none who might destroy or conquer his kingdom. Saint Isidore of Seville, Expositions of Sacred Mysteries or Questions on the Old Testament, On Exodus, Chap 3