She sent out her boughs unto the sea - To the Mediterranean Sea on the one side.
And her branches - Her sucklings. The word is usually applied to little children, and means here the little branches that are nourished by the parent vine.
Unto the river - The Euphrates, for so the river usually means in the Scriptures. The Euphrates on the one side, and the Mediterranean Sea on the other, were the natural and proper boundaries of the country as promised to Abraham. See Psalms 72:8; 1 Kings 4:21. Compare the notes at Psalms 60:1-12.