But Saul and the people spared Agag, and the best of the sheep, and of the oxen, and of the fatlings, and the lambs, and all that was good, and wouldn't utterly destroy them: but everything that was vile and refuse, that they destroyed utterly.
So Samuel is coming with a warning for him and telling him of a mission that God is sending him on. "Now hearken to the voice of the words of the Lord."