"God spoke to Moses right after the death of Aaron's two sons, who brought an [unauthorized] offering before God and died."
The letters of the name of the son who died, Nadav, constitute the words “four sons” - “dalet,” four, and “ben” - son. The Torah spoke about four sons, that is, Adam and his three sons, and their souls were all collected in Nadav and Avihu. The name of Avihu is also a hint at Adam, because it can be read “avi hu” - he is the father.
Whatever Adam did wrong, these also did wrong. And what was it? - Strange fire, the other woman, that is, the first Eve, called Lilith. Adam was united with Lilith before Eve, and that is why he said about Eve, “She will be called a woman” - she, but not the other, Lilith.
The Sages called Adam “restoring his circumcision” because of his prior connection to Lilith, with whom he gave birth to multiple demons. A man (ish) and his wife (ishah) constitute real fire of love together – if God puts his name between them. But without God's name, it constitutes just fire, “ash,” and this is the strange fire of Adam.
Naduv and Avihu were the greatest people of their generation, but they repeated Adam's mistake, and did not get married. In addition, they were drunk with wine – and that again was the sin of Adam, on the opinion that Eve gave him grapes from the Tree of Knowledge of Good and Bad, having made it into wine. Wine has a dual nature, but Adam leaned on the physical side of it.
Additionally, Adam tried to bring everyone, good and bad, into God's presence, and this was a mistake which caused his own exile, and later also other exiles. In this he was not alone, for Moses and King Solomon also tried to bring too many people to God.
Art: Adriaen Jansz. Van Ostade - An Elderly Man Seated Holding A Wineglass