And the Lord hid them in the little town of Zoar, while a great rain of fire fell upon the wicked cities of the plain, until they became a heap of ashes. Only Lot's wife looked back to see the burning cities, and she became a pillar of salt. The next morning when Abraham looked from Hebron down toward the cities of the plain, a great smoke was rising from them like the smoke of a furnace. At last the Lord's promise to Abraham and Sarah came true. A little son was born to them, and they called him Isaac. They were very happy, for though Abraham was a hundred years old, no child had ever been sent them. When he was about a year old they made a great feast for him, and all brought gifts and good wishes, yet the little lad Ishmael, the son of Hagar, Sarah's servant, mocked at Isaac. Sarah was angry, and told her husband that Hagar and her boy must be sent away. So he sent them out with only a bottle of water and a loaf of bread; for God had told Abraham to do as Sarah wished him to do, and He would take care of little Ishmael, and make him the father of another nation. When the water was gone, and the sun grew very hot, poor Hagar laid her child under a bush to die, for she was very lonely and sorrowful. While she hid her eyes and wept, saying, "Let me not see the death of the child," she heard a voice out of heaven telling her not to be afraid. [Illustration: Hagar in the desert] "Arise, lift up the lad," said the voice, "for I will make him a great nation." And God opened her eyes to see a well of water near. Then she filled the empty bottle, and gave the boy a drink, and God took good care of them ever after, though they lived in a wilderness. Ishmael grew up to be an archer, and became the father of the Arabs, who still live in tents as Ishmael did. But the Lord let a strange trial come to the little lad Isaac, also. His father loved and obeyed God, but there were heathen people around them, who worshipped idols, and sometimes killed their own children as a sacrifice to these idols. Abraham brought the best of his lambs and cattle to offer to the Lord; but one day the Lord told Abraham to take his only son Isaac and offer him upon a mountain called Moriah as a burnt sacrifice to God. Abraham had always obeyed God, and believed his word, and now, though he could not understand, he rose up early in the morning and took his young son, with two servants, and an ass loaded with wood, to the place of which God had told him. They were three days on the journey, but at last they came to the high place, where the city of Jerusalem was afterward built, and to the very rock upon which the temple was built long afterward, with its great altar and Holy of Holies. [Illustration: On Mount Moriah] Abraham had left the young men at the foot of the mount, and went with Isaac to the great rock on the top of the mount. "My father," said Isaac, "where is the lamb for a burnt offering?"