Musnad Ahmad 1153:1650

Yahya and Muhammad ibn Ja'far narrated to us, they said: Shu'bah narrated to us, from al-Hakam, from 'Umarah—Ibn Ja'far said: Ibn 'Umayr—from his mother, from 'Aishah, from the Prophet, peace and blessings of Allah be upon him, who said: "A man's child is from his earnings, from the purest of his earnings, so eat from their wealth in good health."