Leviticus 7:15

15. The flesh… shall be eaten the same day The right shoulder, or heave offering, and the wave breast were to be eaten by the priests and their families in the camp, or in Jerusalem, and the remainder of this sacrifice was returned to the offerer, to be eaten by himself and his friends, denoting that they were admitted to a state of intimate companionship with God, sharing part and part with him and his priests, having a standing in his house and a seat at his table. It was an occasion of peculiar joy and gladness, strikingly prefiguring the Lord’s Supper, rightly called the Holy Eucharist, or Thanksgiving, and the blessedness of eating and drinking in the kingdom of God. Luke 14:15.

He shall not leave any… until the morning It would be very improper to expose to putrefaction any thing considered holy. This is supposed to be the ground of the prohibition. Harmer thinks that it is aimed at the Arabian practice of drying the meats presented in sacrifice, which is contrary to both the genius of the Mosaic and of the Christian dispensations. The Gospel does not impart to the believer grace to be put aside for a time of future need, as a soldier puts several days’ rations in his haversack when he is to be separated from his base of supplies, nor does it require him to live on old experiences, since only unbelief can cut him off from access to the bread of life. He is therefore taught to pray, “Give us this day our daily bread.”