Thou hast multiplied the nation, and not increased the joy. Dr. Kay defends this reading, and supposes a contrast of time between this clause and the next; he renders, "Thou didst multiply the nation" (i.
e. in the days of Solomon and again in those of Uzziah) "and not increase the joy; but now," etc. The objection is that the verbs are all in the same tense, the simple preterit, and that there is nothing in the original corresponding to "but now."
Almost all other recent commentators accept the solution offered by the Masoretic reading ( לו for לא), which makes the passage simple and easy: "Thou hast multiplied the nation; its joy thou hast increased; they joy before thee," etc.
According to the joy in harvest. "The joy in harvest" was to the Jews the joy of the Feast of Tabernacles, or in gathering (Exodus 23:16), held when the last fruits were brought in. But the prophet is perhaps taking a wider view, and thinking of the many harvest festivals prevailing throughout Western Asia, all of them originating in gratitude to the Giver of all good, and many of them comprising manifestations of joy more jubilant than those habitual to his sedater countrymen.