Flattered with the honor of her new position as Abraham's wife, and hoping to be the mother of the great nation to descend from him, Hagar became proud and boastful, and treated her mistress with contempt. Mutual jealousies disturbed the peace of the once happy home. Forced to listen to the complaints of both, Abraham vainly endeavored to restore harmony. Though it was at Sarah's earnest entreaty that he had married Hagar, she now reproached him as the one at fault. She desired to banish her rival; but Abraham refused to permit this; for Hagar was to be the mother of this child, as he fondly hoped, the son of promise. She was Sarah's servant, however, and he still left her to the control of her mistress. Hagar's haughty spirit would not brook the harshness which her insolence had provoked. "When Sarai dealt hardly with her, she fled from her face."

Smigret over sin nye ærefulde stilling som Abrahams hustru og i håb om at blive moder til det store folk, der skulle nedstamme fra ham, blev Hagar stolt og pralende og behandlede sin frue med foragt. Gensidig skinsyge forstyrrede freden i det før så lykkelige hjem. Abraham var tvunget til at lytte til begges beklagelser og prøvede forgæves at genoprette harmonien. Skønt det var efter Saras indtrængende tilskyndelse, at han havde giftet sig med Hagar, bebrejdede hun ham nu og kastede skylden på ham. Hun ønskede at få sin rivalinde fjernet; men det nægtede Abraham at gå med til, for han nærede det stolte håb, at Hagar skulle være moder til hans barn - løftets søn. Men Hagar var Saras tjenestepige, og derfor overlod han hende til sin frues opsyn. Den hovmodige Hagar ville ikke finde sig i den hårdhed, hun blev udsat for på grund af sin egen uforskammede opførsel. "Da plagede Saraj hende, så hun flygtede."