That was, as it were, the pre-salvation and therefore pre-Torah, experience. The act of putting lamb's blood on the doorposts was a way of acting out the trust that the Israelites were learning to put into our God. That God provided protection and deliverance in the blood of the Lamb was His act of love--which must, of course, come before we can learn to love Him.
And why bother, afterwards, with that whole Ten Commandments thing - not once, but TWICE?
The first four commandments tell us specifically how to go about loving the Holy One: Remembering that He delivered us, having no other gods besides Him, upholding His Name, and keeping His Sabbaths. The last five tell us how to go about loving our neighbor, "for love does no harm to another" (Rom. 13:10). The fifth commandment bridges the two, for by honoring our early father and mother we also honor the Heavenly Father who set them over us.
Every other commandment of the Torah can be derived out of the Ten, the Ten can be derived from the Two, and the Two ultimately come out of the one: "Love the LORD your God with all your heart, all your soul, and all your might": We are to love our neighbor as ourselves because he too is in the image of God.
Of course, if you understood anything at all about Scripture and our obligations to the One we love and those made in His image, you would not have violated the commandments to love and against slander by slandering xzins.
"Love the LORD your God with all your heart, all your soul, and all your might"