Rabbi Joshua said: Abraham was the first to begin to give a tithe. He took all the tithe of the kings and all the tithe of the wealth of Lot, the son of his brother, and gave (it) to Shem, the son of Noah, as it is said, "And he gave him a tenth of all" (Gen. 14:20).
Shem, the son of Noah, came forth to meet him, and when he saw all the deeds which he had done and all the wealth which he had brought back, || he wondered in his heart. He began to praise, to glorify, and to laud the name of the Most High, saying: "And blessed be God the Most High, who hath delivered thine enemies into thy hand" (ibid.). Abraham arose and prayed before the Holy One, blessed be He, saying: Sovereign of all worlds! Not by the power of my hand, nor by the power of my right hand have I done all these things, but by the power of Thy right hand with which Thou dost shield me in this world and in the world to come, as it is said, "But thou, O Lord, art a shield about me" (Ps. 3:3) in this world; "my glory, and the lifter up of mine head" (ibid.) in the world to come. The angels answered and said: Blessed art Thou, O Lord, the shield of Abraham.