It was narrated from 'Aishah that the Messenger of Allah (ﷺ) said:
'The best (most pure) food a man consumes is that which he has earned himself, and his child (and his child's wealth) is part of his earnings." (FR)
English reference (FR): Vol. 3, Book 12, Hadith 2137 (FR)
Arabic reference (FR): Book 12, Hadith 2220 (FR)