Question: Why did GOD tell Moses to feed the children of Israel before they left Egypt?
Response: I assume you are referring to Exodus chapter 12, the first Passover? This is the inaugural feast of the Jewish ceremonial calendar and was commanded by the Lord as a memorial to His deliverance of Israel from bondage. The unleavened bread speaks to the hastiness of their departure after Pharaoh finally relented following the plague of death upon the first born (cf. Ex.11:1-10; 12:1). But the Passover also symbolizes the Person in whom we are to believe, the One who is our true deliverance from the bondage of sin, Jesus Christ. The unleavened bread represents His sinless humanity. The blood of the sacrifice is symbolic of the blood of Christ, the Passover lamb, a first-born with no broken bones and with no spot or blemish, is symbolic of the perfect first-born Lamb of God (Ps.34:20; Jn.1:36; 19:36; 1Pet.1:19; Rev.5:6); the sprinkling of blood on the door posts in the form of a cross is symbolic of the death He died for us, while the deliverance from the angel of death through this mark of blood symbolizes our deliverance from death to life by His sacrifice (1Cor.5:7).
There is more on this topic and the Jewish ceremonial calendar in the part 5 of the Satanic Rebellion series.
Yours in Christ,