It is narrated from Aishah (may Allah be pleased with her) that he (peace and blessings be upon him) said: "A man's child is part of his earnings, of his purest earnings; so eat from their wealth."
Hammad bin Abi Sulayman narrated it from Ibrahim, from al-Aswad, from Aishah (may Allah be pleased with her), and added in it: "when you need it"; this (addition) is munkar (denounced), as Abu Dawud al-Sijistani said.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النفقات / 15744