كتاب البيوع
Read the English translation first, with the original Arabic directly underneath.
It was narrated that 'Aishah said:
"The Messenger of Allah said: 'The best (most pure) food that a man eats is that which he has earned himself, and his child (and his child's wealth) is part of his earning,"
إِنَّ أَطْيَبَ مَا أَكَلَ الرَّجُلُ مِنْ كَسْبِهِ وَوَلَدُهُ مِنْ كَسْبِهِ