Khadijah: The First to Believe
When revelation first descended and the Prophet ﷺ came home trembling, one person wrapped him in a cloak and in unshakeable certainty: his wife.
The cave of Hira, the fortieth year of his life. The angel pressed him and said: "Iqra' — Read!" And Muhammad ﷺ came down the mountain with his heart pounding, and he did not go to a chief, or a poet, or a warrior.
He went home. "Cover me, cover me," he said. And Khadijah رضي الله عنها covered him, and listened, and when he said, "I fear for myself," she answered with words the ummah has never forgotten:
"Never, by Allah! Allah will never disgrace you. You keep the ties of kinship, you carry the weak, you earn for the destitute, you honor the guest, and you help against the blows of fate."
She did not say "calm down." She reasoned from his character to his Lord's care — the first person in history to believe in the final Prophet, before a single verse beyond the first had come down.
She spent her wealth on the message until the boycott years ate it away. She bore his children. For her sake, years after she passed, the Prophet ﷺ would send meat to her old friends, and when he heard her sister's voice — so like hers — his face would change with remembrance. Aisha said she was never jealous of any woman as she was of Khadijah, a woman she had never met (Bukhari 3818).
And Jibril himself came with a message: "Give Khadijah glad tidings of a house in Paradise made of qasab, in which there is no noise and no fatigue" (Bukhari 3820).
The first believer was a believer in her husband's truthfulness before the world knew what wahy was. Sidq recognizes sidq.
Sources: Sahih al-Bukhari 3 (beginning of revelation); Sahih al-Bukhari 3818; Sahih Muslim 2435