瑜伽師地論略纂 2.127

2.127

Regarding "the Tathāgata's messenger": For instance, there was a woman who became pregnant, and the Buddha predicted it would be a boy. Later, before the child was born, the mother died, and non-Buddhists mocked and criticized the Buddha's prediction as having no proof. On the day the mother was cremated, the Buddha ordered a messenger to enter the fire and retrieve the child; although the mother had died, her child was not dead. The messenger entered the fire and carried the child back; through the Buddha's sustaining power, the fire did not burn the messenger. This was because the Buddha had only predicted the child, not the mother.