Issachar is a strong ass couching down between two burdens:

Then they hasted, and took every man his garment, and put it under him on the top of the stairs, and blew with trumpets, saying, Jehu is king.

His bones are as strong pieces of brass; his bones are like bars of iron.

A merry heart doeth good like a medicine: but a broken spirit drieth the bones.

By long forbearing is a prince persuaded, and a soft tongue breaketh the bone.