It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: A person eats the purest thing, and that is what he earns himself, and a person's children are also from his earnings.
Hadith Referenceمسند احمد / مسند النساء / 25611
Hadith Gradingحکم دارالسلام:حديث حسن لغيره، وهذا إسناد ضعيف لجهالة عمة عمارة