The Israelites obeyed God. They had taken the blood of the lamb and put it over their doorway and cooked and eaten the lamb the way that God had instructed them to. Because of this they were not only safe when the death angel passed over, they received favor.
Exodus 12:29-35 NKJV
“And it came to pass at midnight that the Lord struck all the firstborn in the land of Egypt, from the firstborn of Pharaoh who sat on his throne to the firstborn of the captive who was in the dungeon, and all the firstborn of livestock. So Pharaoh rose in the night, he, all his servants, and all the Egyptians; and there was a great cry in Egypt, for there was not a house where there was not one dead. Then he called for Moses and Aaron by night, and said, ‘Rise, go out from among my people, both you and the children of Israel. And go, serve the Lord as you have said, and be gone; and bless me also. And the Egyptians urged the people, that they might send them out of the land in haste. For they said, ‘We shall all be dead.’ So the people took their dough before it was leavened, having their kneading bowls bound up in their clothes on their shoulders. Now the children of Israel had done according to the word of Moses, and they had asked from the Egyptians articles of silver, articles of gold, and clothing.”
The Israelites left Egypt with treasures because the Lord had given them favor with the Egyptians.
Exodus 12:36 NKJV
“And the Lord had given the people favor in the sight of the Egyptians, so that they granted them what they requested. Thus they plundered the Egyptians.”
Like the Israelites, we can obtain favor with our enemy through taking communion.