Albert Barnes Commentary Ezekiel 19:10

"Thy mother was like a vine, in thy blood, planted by the waters: it was fruitful and full of branches by reason of many waters." — Ezekiel 19:10 (ASV)

Your mother - Judah or Jerusalem. Jehoiachin is still addressed.

In your blood - Blood is equivalent to “life” (Genesis 9:4). The clause is equivalent to Your mother is a vine, living in your blood, that is, in the life of you and of your children. The excellency of a vine is in her fruitful branches; the glory of a mother in her noble children. Jeremiah was to write Jehoiachin childless (see the note at Jeremiah 22:30); Ezekiel here takes a general view of the king and princes of the blood royal.