Arcana Coelestia #406
406. 'Lamech' means vastation, that is, the fact that faith is no more. This becomes clear from verses 23-24, below, which state that 'he killed a man (vir) to his wounding, and a little one to his bruising'. At that point 'man' is used to mean faith, 'a little one' or little child to mean charity.
Numbers 9:15
15
On the day that the tabernacle was raised up, the cloud covered the tabernacle, even the Tent of the Testimony: and at evening it was over the tabernacle as it were the appearance of fire, until morning.