Charles Ellicott Commentary Genesis 49:11

"Binding his foal unto the vine, And his ass`s colt unto the choice vine; He hath washed his garments in wine, And his vesture in the blood of grapes:" — Genesis 49:11 (ASV)

Binding his foal... — Having declared the spiritual prerogative of Judah, the patriarch now foretells that his land would be so rich in vineyards that the traveler would tie his ass to the vine, as a tree found abundantly everywhere.

Choice vine is, literally, the vine of Sorek, a kind much valued, bearing a purple berry, small but luscious, and without stones. The abundance of grapes is next hyperbolically described as so great that their juice would be used like water for the commonest purposes.

Blood of grapes especially refers to the juice of the red kinds, which were more valued in the East than white.