Midrasch zu Könige I 17:20

At the time the Holy One, blessed be He, said to Moses: Come now, therefore, and I will send thee unto Pharaoh (Exod. 3:10), Moses replied: “Master of the Universe, I cannot leave, for Jethro welcomed me and opened his home unto me, and I am like a son unto him.” If one opens his door to his fellowmen, the latter owes him his very life. You find this occurred at the time Elijah visited the widow in Zarephath. After her son’s death, he began to plead: O Lord my God, hast Thou also brought evil upon the widow with whom I sojourned, by slaying her son? (I Kings 17:20). Whereupon, The Lord harkened unto the voice of Elijah; and the soul of the child came back into him, and he revived (ibid., v. 22).