Haggai 1:3 - Albert Barnes' Notes on the Bible

And the word of the Lord came - ^o “Before, he prophesied nothing, but only recited the saying of the people; now he refutes it in his prophecy, and repeats, again and again, that he says this not of himself, but from the mind and mouth of God.” It is characteristic of Haggai to inculcate thus frequently, that his words are not his own, but the words of God. Yet “the prophets, both in their threats and prophecies, repeat again and again, “Thus saith the Lord,” teaching us, how we should prize the word of God, hang upon it, have it ever in our mouth, reverence, ruminate on, utter, praise it, make it our continual delight.”