The birth of Isaac, bringing, after a lifelong waiting, the fulfillment of their dearest hopes, filled the tents of Abraham and Sarah with gladness. But to Hagar this event was the overthrow of her fondly cherished ambitions. Ishmael, now a youth, had been regarded by all in the encampment as the heir of Abraham's wealth and the interior of the blessings promised to his descendants. Now he was suddenly set aside; and in their disappointment, mother and son hated the child of Sarah. The general rejoicing increased their jealousy, until Ishmael dared openly to mock the heir of God's promise. Sarah saw in Ishmael's turbulent disposition a perpetual source of discord, and she appealed to Abraham, urging that Hagar and Ishmael be sent away from the encampment. The patriarch was thrown into great distress. How could he banish Ishmael his son, still dearly beloved? In his perplexity he pleaded for divine guidance. The Lord, through a holy angel, directed him to grant Sarah's desire; his love for Ishmael or Hagar ought not to stand in the way, for only thus could he restore harmony and happiness to his family. And the angel gave him the consoling promise that though separated from his father's home, Ishmael should not be forsaken by God; his life should be preserved, and he should become the father of a great 147 nation. Abraham obeyed the angel's word, but it was not without keen suffering. The father's heart was heavy with unspoken grief as he sent away Hagar and his son.

Isaks fødsel, som efter et helt livs ventetid betegnede opfyldelsen af deres inderligste håb, fyldte Abrahams og Saras telte med glæde. Men for Hagar betød denne begivenhed tilintetgørelsen af hendes stolteste forhåbninger. Ismael, der nu var en ung mand, var af alle i lejren blevet betragtet som arving til Abrahams rigdom og de velsignelser, der var lovet hans efterkommere. Nu blev han pludselig sat til side og i skuffelse herover hadede både moder og søn Saras barn. Den almindelige glæde forøgede blot deres misundelse, indtil Ismael dristede sig til åbent at håne arvingen til Guds løfte. Sara så i Ismaels ustyrlige natur en stadig kilde til splid, og hun henvendte sig til Abraham og opfordrede ham til at sende Hagar og Ismael bort fra lejren. Patriarken sørgede dybt. Hvordan kunne han sende sin søn Ismael bort, som han stadig elskede? I sin kvide søgte han guddommelig bistand. Herren befalede ham gennem en hellig engel at efterkomme Saras ønske. Hans kærlighed til Ismael eller Hagar måtte ikke være en hindring, for det var den eneste måde, hvorpå han kunne genoprette freden og lykken i sin familie. Og engelen gav ham det trøsterige løfte, at selv om Ismael måtte forlade sin faders hus, ville Gud ikke svigte ham. Hans liv ville blive skånet, og han skulle blive fader til et stort folk. Abraham adlød engelens ord, men ikke uden dyb smerte. Faderens hjerte tyngedes af uudtalt sorg, da han sendte Hagar og sin søn bort.