Jamieson, Fausset and Brown on Habakkuk 1:6

6. I raise up--not referring to God's having brought the Chaldeans from their original seats to Babylonia (see on Is 23:13), for they had already been upwards of twenty years (since Nabopolassar's era) in political power there; but to His being about now to raise them up as the instruments of God's "work" of judgment on the Jews (2Ch 36:6). The Hebrew is future, "I will raise up."

bitter--that is, cruel (Jr 50:42; compare Jud 18:25, Margin; 2Sa 17:8).

hasty--not passionate, but "impetuous."