Hagar was proud and boastful, and carried herself haughtily before Sarah. She flattered herself that she was to be the mother of a great nation God had promised to make of Abraham. And Abraham was compelled to listen to complaints from Sarah in regard to the conduct of Hagar, charging Abraham with wrong in the matter. Abraham is grieved and tells Sarah that Hagar is her servant, and that she can have the control of her, but refuses to send her away, for she is to be the mother of his child, through whom he thinks the promise is to be fulfilled. He informs Sarah that he should not have taken Hagar for his wife if it had not been her special request. SR 77.3
Abraham was also compelled to listen to Hagar's complaints of abuse from Sarah. Abraham is in perplexity. If he seeks to redress the wrongs of Hagar he increases the jealousy and unhappiness of Sarah, his first and much-loved wife. Hagar flees from the face of Sarah. An angel of God meets her and comforts her and also reproves her for her haughty conduct, in bidding her return to her mistress and submit herself under her hands. SR 78.1
After the birth of Ishmael the Lord manifested Himself again to Abraham and said unto him, “I will establish My covenant between Me and thee and thy seed after thee in their generations for an everlasting covenant.” Again the Lord repeated by His angel His promise to give Sarah a son, and that she should be a mother of many nations. Abraham did not yet understand the promise of God. His mind immediately rested upon Ishmael, as though through him would come the many nations promised, and he exclaimed, in his affection for his son, “O that Ishmael might live before Thee!” SR 78.2
Again the promise is more definitely repeated to Abraham: “Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish My covenant with him for an everlasting covenant, and with his seed after him.” Angels are sent the second time to Abraham on their way to destroy Sodom, and they repeat the promise more distinctly that Sarah shall have a son. SR 78.3