In Genesis 4:23, this signifies to extinguish faith. (Arcana Coelestia 427)

'The slain of Jehovah' signify people who turn truths into falsities, which causes them to perish.

'The slain,' in Lamentations 2:12 signify people who do not know what the truths of faith mean.

'The slain' when referring to the Lord in Revelation 5 means the separation of everything from the divine. In denial of His divinity, He is spiritually slain to people and this denial causes a state of separation from Him.

(Referenser: Lamentations 2; The Apocalypse Explained 828)

1529. It is very well known in heaven, but not so well known in the world of spirits, where so great a light comes from, namely from the Lord. And what is astonishing, the Lord appears to celestial angels in the third heaven as the Sun, but to spiritual angels as the Moon. There is no other source of light. But the intensity of the light angels experience depends on how celestial and spiritual they are, and the nature of the light depends on the nature of these qualities. Thus the Lord's celestial and spiritual itself shows itself before angels' external vision by means of the light.