Bible Dictionary
SINEW
A sinew is a tendon or tough band connecting muscle and bone. Scripture uses the term literally for the body and figuratively for stubbornness, as in an “iron sinew.”
Biblical Usage
The sinew of Jacob’s hip is associated with the tradition explaining Israel’s avoidance of that sinew. Sinews appear in descriptions of the body and the restoration of dry bones, while an obstinate neck is compared to an iron sinew.