'Bowels' in the Bible

When thy days are fulfilled, and thou shalt sleep with thy fathers, I will set up thy seed after thee, that 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, who came forth from my bowels, seeketh my life: how much more may this Benjamite now do it ? let him alone, and let him curse; for Jehovah hath bidden him.

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