He knows firsthand because he's experiencing it in their relationship. Before this relationship, he was probably against adultery, Hozier From Eden Song Lyrics Analysis

When the narrator "inserts Heaven’s home"—a phrase that feels like plugging a key into a lock that doesn't belong to you—they aren't just visiting. They are trespassing into a state of grace. To be in this context isn't just about being surprised by affection. It’s the shock of a "serpent" discovering that they are actually capable of being loved back.

The phrase you’ve provided appears to be a slightly misremembered or creatively modified lyric from 2014 hit, "From Eden" . In the original song, the line is actually: "I was astonished to find me / After the way you were kind to me / Baffled, bewildered by the size of your love" .

: Inserting a sense of "home" into a relationship that feels like a "wretched" sin creates a haunting duality. It suggests that maybe the truest heaven isn't a place you're born into, but a place you have to "give hell" just to live through.

There is a specific kind of vertigo that comes with finding exactly what you need in a place you were taught to fear. In the track Hozier doesn't just sing about love; he sings about the theft of paradise .