The so-called song of Lamech is in strong contrast with the mood created by the previous verses. Along with cultural and social development there is also the growth of evil. This little piece – together with the following verse (v.24) – constitutes the center of a speech whose frame consists of the two birth announcements (vv. 20-22 and v. 25). It is a wild song and describes, after an apparent distraction from the theme, the climate of increasing violence on the earth inhabited by man.
The second part of the verse presents a lexical problem. It is a synonymic parallelism, that is, two sentences that are taken up again to formulate and to reinforce the idea that one wants to give. However, the term man (in Hebrew ‘ish) matches the term boy (in Hebrew yeled). But this correspondence is not characteristic of true parallelism. In fact, one would expect that man corresponds, for example, to son of a man (see Nm 23:19 and also Sal 8: 5). Moreover, the most striking comparison is the previous sentence, where Ada and Zillah are taken with the synonym wives of Lamech. The term yeled, on the other hand, covers a wide range of ages.
Basically, it is a way to say that even the smallest affront made by people of all ages, is repaid with an incredibly disproportionate violence. The flood which marks the apex of this section, is not caused by sin, but by violence that corrupts the human heart.