John Calvin on Ezekiel 17:7

He now detects, under a figure, the perfidy of Zedekiah, since he very soon applied himself to the king of Egypt, and bent his roots and branches towards him, that they might be irrigated. I do not disagree with the opinion of those who think that the Prophet alludes to an Egyptian custom; for we know that they dug furrows through which water flowed through the whole region: hence the fruitfulness of the soil; and thus Egypt is elsewhere compared to a garden. (Deuteronomy 11:10.) Whatever the meaning is, the Prophet shows that Zedekiah was deceived by a foolish confidence when he thought himself safe under the protection of the king of Egypt; for he had said that the seed was so planted that the vine did not rise to a great height, but spread itself under the wings of the eagle. But Zedekiah despised the king of Babylon, thinking that he should improve his condition by entering into a treaty with the king of Egypt. It now follows —

Ezekiel 17:8

8. It was planted in a good soil by great waters, that it might bring forth branches, and that it might bear fruit, that it might be a goodly vine.

8. Super agrum bonum That is, “in a good soil.” — Calvin. juxta aquas multas Or, “copious.” — Calvin. ipsa plantara erat, ut produceret folia, et proferret fructum ut esset in vitem magnificam. Or it is usually rendered, “others have a beautiful vine:” אדר, ader, signifies properly to strengthen: hence it may be translated a strong vine; but here it means beautiful, elegant, or superb. — Calvin.