And they shall take some of the blood and put it on the two doorposts and on the lintel of the houses. Exodus 12:7. FH 222.1
The Lord gave Moses special directions for the children of Israel in regard to what they must do to preserve themselves and their families from the fearful plague that He was about to send upon the Egyptians. Moses was also to give his people instructions in regard to their leaving Egypt. On that night, so terrible to the Egyptians and so glorious to the people of God, the solemn ordinance of the Passover was instituted. By the divine command, each family, alone or in connection with others, was to slay a lamb or a goat “without blemish,” and with a bunch of hyssop sprinkle its blood on “the two side posts, and on the upper door post” of their houses, as a token, that the destroying angel, coming at midnight, might not enter that dwelling. They were to eat the flesh roasted, with bitter herbs, at night, as Moses said, “with your loins girded, your shoes on your feet, and your staff in your hand; and ye shall eat it in haste: it is the Lord's passover.” This name was given in memory of the angel's passing by their dwellings; and such a feast was to be observed as a memorial by the people of Israel in all future generations. FH 222.2
Leaven works secretly and is a fit emblem of hypocrisy and deceit. And on this occasion the children of Israel were to abstain from leavened bread, that their minds might be impressed with the fact that God requires truth and sincerity in His worship. The bitter herbs represented their long and bitter servitude in Egypt, also the bondage of sin. It was not enough to simply slay the lamb and sprinkle its blood upon the doorposts, but it was to be eaten, thus representing the close union which must exist between Christ and His followers. FH 222.3
A work was required of the children of Israel to prove them and to show their faith in the great deliverance which God had been bringing about for them. In order to escape the terrible judgment about to fall upon Egypt, the token of blood must be seen upon their houses. And they were required to separate themselves and their children from the Egyptians and gather them into their own houses; for if any of the Israelites were found in the dwellings of the Egyptians, they would fall by the hand of the destroying angel. They were also directed to keep the feast of the Passover for an ordinance, that when their children should inquire what such service meant, they should relate to them their wonderful preservation in Egypt.—Signs of the Times, March 25, 1880. FH 222.4