God's Oath Barring the Seed of Amalek and David's Sentence on the Amalekite

(Exodus 17:16:) "And he said: Because a hand is upon the throne of the LORD, the LORD has a war with Amalek from generation to generation." It is taught in the name of Rabbi Eleazar: The Holy One, blessed be He, swore an oath and said, "My right hand, my right hand; My throne, My throne! If gentiles come from any of the nations, I will accept them; but from the seed of Amalek I will not accept." And David also acted thus, as it is said (in II Samuel 1:13): "And David said to the young man who told him: From where are you? And he said: I am the son of an Amalekite sojourner." Rabbi Isaac said: He was the son of Doeg the Edomite. And David said to him (in II Samuel 1:16): "Your blood be upon your own head." ["Your bloods" is written.] Much blood you spilled in Nob, the city of the priests.