How could Abraham say to Sarah concerning Hagar, "Do with her as you please," and how could he fulfill Sarah's request to cast out Hagar and leave her in a remote, uncared-for place?

Belief in the Messengers is one of the fixed pillars of faith; no faith or Islam is valid without it. It is established by the Quran, Sunnah, and the consensus of Muslims. Belief in the Messengers is not limited to acknowledging their existence, but also includes love, reverence, veneration, and obedience to what they commanded. It is obligatory to believe in all Messengers and not differentiate between them. One should not accuse a person's opinion in religion, but rather the opinion should be accused if it contradicts Islamic law, for what appears to be wrong may have a hidden interpretation and wisdom.

The narration that mentions Abraham saying to Sarah: "Do with her what you wish" is from the accounts of the People of the Book, which are neither affirmed nor denied, and should be rejected if they imply any imperfection on the part of a prophet. Scholars have stated that Abraham (peace be upon him) was the one who took Hagar and his son Ishmael to Makkah by divine revelation, and this indicates submission to God's command, not injustice or imperfection.