The ancient Hebrews perceived that there were poetical portions in their sacred texts, as shown by their entitling as songs or chants passages such as Exodus 15:1-19 and Numbers 21:17-20; a song or chant (shir) is, according to the primary meaning of the term, poetry. The question as to whether the poetical passages of the Old Testament show signs of regular rhythm or meter is yet unsolved.
The employment of unusual forms of language cannot be considered as a sign of ancient Hebrew poetry. In the sentences of Noah the form "lamo" occurs. But this form, which represents partly "lahem" and partly "lo", has many counterparts in Hebrew grammar, as, for example, "kemo" instead of "ke-"; or "-emo" = "them"; or "-emo" = "their"; or "clemo" = "to them"—forms found in passages for which no claim to poetical expressions is made. Then there are found "ḥayeto" = "beast", "osri" = "tying", and "yeshu'atah" = "salvation"—three forms that probably retain remnants of the old endings of the nominative, genitive, and accusative: "u(n)," "i(n)," "a(n)."
Again, in Lamech's words, "Adah and Zillah, hear my voice; ye wives of Lamech, harken unto my speech", the two words "he'ezin" and "imrah" attract attention, because they occur for the first time in this passage, although there had been an earlier opportunity of using them: in Genesis 3:8 and 3:10, "He'ezin" = "to harken" could have been used just as well as its synonym "shama'" = "to hear".
Furthermore, "imrah" = "speech" might have been used instead of the essentially identical "dabar" in Genesis 9:1 and following, but its earliest use is, as stated above, in Genesis 4:23. In place of "adam" = "man" "enosh" is employed. (compare the Aramaic "enash").
A systematic review of similar unusual forms of Hebrew grammar and Hebrew words occurring in certain portions of the Old Testament. Such forms have been called "dialectus poetica" since the publication of Robert Lowth's "Prælectiones de Sacra Poesi Hebræorum" iii. (1753); but this designation is ambiguous and can be accepted only in agreement with the rule a parte potiori fit denominatio for some of these unusual forms and words are found elsewhere than in the "songs" of the Old Testament.