1 tn The clause simply has “I am guilty.” It is the same type of construction found in v. 24. It is also the opposite of that in v. 20. GKC 317 §107.n lists this as an example of the use of the imperfect to express an obligation or necessity according to the judgment of others; it would therefore mean “if I am to be guilty.”
2 tn The demonstrative pronoun is included to bring particular emphasis to the question, as if to say, “Why in the world…” (see R. J. Williams, Hebrew Syntax, 24, §118).
3 tn The verb means “tire oneself”; see 3:17.
4 tn Here הֶבֶל (hevel, “breath, vapor, vanity”) is used as an adverb (adverbial accusative).