I should have said "his doorposts" meaning the doors to our heart are his.
I've been giving this subject a lot of thought; and I know you to be a very deep thinker.
Another part of this thought, is that I believe that the blood that was on the doorposts were the making of a threshold covenant. The head of the household would make such a covenant to someone who he invited into his home, and give them protection as his own family.
I made note of some information regarding this subject here:
YHWH's Table (Part 8A)
I find this verse from the story of Lot and the messengers to be very interesting:
(CLV) Gn 19:3
But he urged them so intensely that they turned in with him and entered his house. He made a feast for them and baked unleavened bread, and they ate.
Lot went all out to protect these messengers that he had invited into his home.
Interestingly, in the story of Moses, YHWH was telling his people to kill the god of the Egyptians, and to smear the blood of their god on their doorposts, right in front of them. Moses wanted to go away to do this; but YHWH really put their trust in him to a test.
That said, I've begun to set the stage to pick your brain.
In addition to all the rest of what we can gather from that event, the blood was to protect only the firstborn of each house from the death angel. What do you suppose that might mean, especially in relationship to the other information that was presented?
The more I dig for the meaning of his word, the more I realize that I've only scratched the surface.