Issachar is a strong donkey, lying down between the sheepfolds.

Genesis 49:15
He saw that his resting place was good and that his land was pleasant, so he bent his shoulder to the burden and submitted to labor as a servant.

Numbers 32:16
Then the Gadites and Reubenites approached Moses and said, "We want to build sheepfolds here for our livestock and cities for our little ones.

Judges 5:16
Why did you sit among the sheepfolds to hear the whistling for the flocks? In the clans of Reuben there was great indecision.

Psalm 68:13
Though you lie down among the sheepfolds, the wings of the dove are covered with silver, and her feathers with shimmering gold."

Psalm 78:70
He chose David His servant and took him from the sheepfolds;

Issachar is a strong ass couching down between two burdens: