In other words, because he was a blacksmith, who helped to make weapons which could be used to kill more efficiently, he invokes his ancestor Cain's sin of murder.

[1] In Antiquities of the Jews, Josephus says that "Tubal exceeded all men in strength, and was very expert and famous in martial performances, ... and first of all invented the art of working brass.

[3] Richard Coggins suggests it "may be a variant of the same tradition which lists Tubal in the table of nations" at Gen 10, as a land well known for metalwork.

[4] In the Book of Jasher (Pseudo-Jasher) (1751), the name of Tubal-Cain is explained by Zillah, his mother: "After I had withered away have I obtained him from the Almighty God" (2:24).

The intended conclusion here is that "Cain" (given earlier in the idea of "obtaining") was merged with "Tubal", a word seemingly to denote "withering" by contextual speculation.