In the time of King Suleiman, a vizier's wife had borne nine daughters in a row. As her tenth pregnancy advanced, the vizier grew frantic for a son. He warned his wife that if she bore another girl he would punish her terribly.
The tenth child was born, and it was a daughter. The wife, in terror, whispered the truth only to her midwife. The midwife had attended another birth that same day, a son born to a washerwoman in the same city. She quickly switched the two infants. The vizier's wife kept the boy. The washerwoman, returning home, found a girl in her cradle.
The washerwoman was not a woman to be silenced by power. She brought the case to the sultan's court and accused the midwife and the vizier's wife of stealing her son. The sultan and his advisers were stumped. Two infants, two mothers, two identical days of birth. How could anyone prove which child belonged to which mother?
Someone in the court remembered the Jewish Rabbi, a scholar famous for untangling impossible disputes. He was summoned. His ruling was simple. He asked each mother to fill a vessel of equal weight with her own milk. Two bowls were brought and weighed.
The washerwoman's milk was visibly heavier than the vizier's wife's. The rabbi explained. The milk of a mother nursing a male child is heavier than the milk of a mother nursing a female child, because the male child draws a richer composition. Therefore the washerwoman, producing the heavier milk, was the true mother of the boy.
The sultan accepted the ruling. The washerwoman got her son back. The rabbi then turned his wisdom to appeasing the vizier, calming his fury at his wife, and negotiating a peace between them. The tenth daughter remained with her mother, safe and named (Gaster, Exempla No. 364).
The story ends where the biological claim begins. The Torah is a book of law, but the sages who study it learn to read ledgers that Pharaoh's court never noticed, including the ledger written into a mother's milk.