Arcana Coelestia #4401
4401. 'And he set up an altar there' means interior worship. This is clear from the meaning of 'setting up an altar' as worship, for the altar was the chief representative of the Lord, 921, 2777, 2811, and therefore the chief feature of worship. By worship here is meant interior worship originating in the Divine Spiritual, dealt with in the paragraph following this.
Arcana Coelestia #533
533. Since nothing further is mentioned about Lamech apart from the fact that be beget sons and daughters, who are the conceptions and births of such a Church, there is no need to pause any longer over him. What these births, or sons and daughters, were, becomes clear from the Church, for the character of a Church determines that of its offspring. Both those Churches called Methuselah and Lamech breathed their last just before the flood.