St Anthony of Padua, Sermon 25:
We are told in the second book of Exodus, that Moses struck the Egyptian, and hid his body in the sand (Ex 2,12). Moses is ‘from the waters’, and he represents the penitent, awash with the waters of sorrow. He must strike the Egyptian, mortal sin, in contrition, and bury him under the sand in confession. St Augustine says: “If you uncover, God will cover; if you hide, God will find out.” He who discloses his sins ‘hides the Egyptian’- hides it from God, I say, even as he reveals it to the priest. In Genesis, it says that Rachel hid the idols of Laban (cf. Gn 31,34). Rachel (‘a sheep’) is the penitent soul who should hide the idols (mortal sins) that belong to Laban (the devil). Blessed are those whose sins are covered (Ps 31,23).
St Anthony of Padua, Sermon 5:
So you find in Exodus that Moses hid the Egyptian he had slain in the sand (Ex 2,12), because the just man ought to strike down mortal sin in confession, and hide it with the satisfaction of penance.
St Anthony of Padua, Sermon 105:
Pharao sought to kill Moses. But he fled from his sight, and abode in the land of Madian: and he sat down beside a well. (Ex 2,15)
You too should flee, my beloved; because the devil wants to kill you. Go and live in the land of Madian (which means ‘of judgement’), so that you may judge your own land, and not be judged by God. Sit by the well of humility, from which you may draw water springing to eternal life (cf. Jn 4,14). Flee away, my beloved. It says in Genesis that Rachel said to Jacob:
Behold, Esau thy brother threateneth to kill thee. Now therefore, my son, hear my voice: Arise and flee to Laban, my brother, to Haran; and thou shalt dwell with him. (Gn 27,42)
Hairy Esau is the world, full of many vices. He threatens to kill you, my son. Flee away, then, my beloved, to Laban (meaning ‘whitening’), Jesus Christ who will make you whiter than snow (Ps 50,9) from your sins. He is in Haran (‘on high’), and there you will live with him; because God dwells on high (Ps 112,3). Flee away, then, my beloved!
St Thomas Aquinas, (Summa Theologica, ii, 2, q. 60, art 6):
Moses seems to have slain the Egyptian by authority received as it were, by divine inspiration; this seems to follow from Acts 7:24-25, where it is said that “striking the Egyptian … he thought that his brethren understood that God by his hand would save Israel [Vulgate: ‘them’].” Or it may be replied that Moses slew the Egyptian in order to defend the man who was unjustly attacked, without himself exceeding the limits of a blameless defence. Wherefore Ambrose says (De Offic. i, 36) that “whoever does not ward off a blow from a fellow man when he can, is as much in fault as the striker”; and he quotes the example of Moses. Again we may reply with Augustine (QQ. Exod. qu. 2) [Cf. Contra Faust. xxii, 70] that just as “the soil gives proof of its fertility by producing useless herbs before the useful seeds have grown, so this deed of Moses was sinful although it gave a sign of great fertility,” in so far, to wit, as it was a sign of the power whereby he was to deliver his people.