Verses 11-14 are the first of the numerical sayings, although the common formula “Three things . . . four. . .” is not used to introduce it. Each of the four verses begins with a Hebrew term that means literally “a generation,” used here to introduce a group of people who sin in a particular way. Scott labels the saying “Four kinds of sinners.” Some commentators suggest that there is a sequence in the wickedness described, leading up to the brutality of the fourth group of people.
“There are those who curse their fathers”: “There are those who” introduces people who frequently or habitually do what follows. For “curse their fathers” see 20.20.
“And do not bless their mothers”: This line is parallel to the previous line; it extends and emphasizes its meaning. “Do not bless” says the same thing as “curse”. Since the sense of the two lines is very similar, they may be combined to say, for example, “Some people curse their parents” or “Some people curse their father and even their mother” (Contemporary English Version).
Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Proverbs. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .
