It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: The purest thing a person eats is that which he earns himself, and a person's children are also part of his earnings.
Hadith Referenceمسند احمد / مسند النساء / 24032
Hadith Gradingحکم دارالسلام:حديث حسن لغيره، وهذا إسناد ضعيف لجهالة عمة عمارة