'Bowels' in the Bible

And when thy days be fulfilled, and thou shalt sleep with thy fathers, I will set up thy seed after thee, which shall proceed out of thy bowels, and I will establish his kingdom.

And David said to Abishai, and to all his servants, Behold, my son, which came forth of my bowels, seeketh my life: how much more now may this Benjamite do it? let him alone, and let him curse; for the LORD hath bidden him.

But Amasa took no heed to the sword that was in Joab's hand: so he smote him therewith in the fifth rib, and shed out his bowels to the ground, and struck him not again; and he died. So Joab and Abishai his brother pursued after Sheba the son of Bichri.