Behold. Figure of speech Asterismos (App-6), for emphasis, calling attention to the reference to Isaiah 52:7, the the hypotheticalsecond Isaiah, 100 years before he is supposed by modern critics to have lived.
keep thy solemn feasts. Figure of speech. Polyptoton. App-6. Hebrew "feast thy solemn feasts": used for great emphasis. Reference to Pentateuch (Deuteronomy 16:16, &c.; Nah 23:21, &c). App-92.
the wicked. Hebrew [the man of] Belial. See note on Nahum 1:11.