'Bone' in the Bible

Then all the tribes of Israel came to David in Hebron and said, Truly, we are your bone and your flesh.

You are my brothers, my bone and my flesh; why are you the last to get the king back again?

And say to Amasa, Are you not my bone and my flesh? May God's punishment be on me, if I do not make you chief of the army before me at all times in place of Joab!