Malachi. Malachi, meaning “my messenger” or “my angel,” was the last of the Old Testament prophets, prophesying in about 430 b.c., although the precise date is very uncertain. This was at least several decades after the ministry of Haggai and Zechariah. The temple was completed and its worship restored, but it had already become corrupt. Malachi preached against the same sins that Nehemiah encountered when he came to Jerusalem.

I loved Jacob. Note Romans 9:11-13, where God's choice of Jacob over Esau, even before they were born, is cited as an evidence and example of God's sovereign choice. Their later lives, of course, confirmed the wisdom of God's selection. However, as far as Malachi's prophecy is concerned, this fact is given mainly as evidence of God's undying love for the chosen nation descended from Jacob.

dragons of the wilderness. These “dragons” (Hebrew tannin) are mentioned fairly frequently in Scripture—first in Genesis 1:21, where the word is translated “whales.” It is best understood as a generic term for what we now call “dinosaurs,” either great marine reptiles or land dinosaurs, depending on context.

ye say, Wherein. This is the fifth of at least ten rhetorical questions placed by Malachi on the lips of those he was rebuking. This dialectic method of argumentation, adopted for the first time in Scripture here by Malachi, was appropriated by later Jewish teachers as a popular instructional method.

a corrupt thing. God had given explicit instruction to sacrifice only animals that were without blemish (e.g., Leviticus 22:18-24). Yet, despite the Lord's punishment of their fathers, as well as His blessing upon the returned exiles, they quickly went back to ignoring or breaking His commandments, this time with the motive of pure greed on the part of both priests and people.