E.W. Bullinger's Companion Bible Notes - Isaiah 9:3
Thou: i.e. Jehovah* hast. This is the Figure of speech Prolepsis , by which the future is prophetically spoken of as present, or past. and not increased the joy. The difficulty is not removed by reading lo , "to him", instead of l'o , "not" (which is the marginal reading of Hebrew text, and is followed by the Revised Version. Dr. C. D. Ginsburg suggests that the word in question, haggil'o, was wrongly divided into two words, and the last syllable ( l'o) was treated as a separate word.... read more
E.W. Bullinger's Companion Bible Notes - Isaiah 9:2
that walked in darkness = the walkers in darkness. have men = saw. Quoted in Matthew 4:14-16 . read more