Musnad Ahmad 1153:1278

Yahya ibn Zakariyya narrated to us, al-A’mash narrated to us, from ‘Umarah, from his paternal aunt, from ‘Aishah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, the best of what you eat is from your own earnings, and indeed, your children are from your earnings."