Charles Ellicott Commentary Proverbs 21:1

"The king`s heart is in the hand of Jehovah as the watercourses: He turneth it whithersoever he will." — Proverbs 21:1 (ASV)

As the rivers of water.— Channels for irrigation . He turns the heart of the king, whose favour is as the latter rain (Proverbs 16:15) and dew (Proverbs 19:12), now towards one suppliant and now towards another, as He thinks fit, for “the hearts of kings are in His rule and governance.”