In Luke 4:23 we read “... You will quote this proverb to Me, ‘Physician, heal yourself’...” Do you know the origin of this proverb? – B.B.
I don't know its origin, though I suspect some form of the saying exists in many parts of the world. The info at https://en.wikipedia.org/wiki/Physician,_heal_thyself seems to be accurate. Take a peek.
Another example of a proverb not found in Proverbs is found in Ezek 18:1-3.
Of course proverbs exist in every culture. The biblical book of Proverbs contains several hundred, and their purpose is to help us to live wisely, in the knowledge and discipline of the Lord. Solomon himself wrote some 3000 (1 Kings 4)! Jesus isn't commenting on the truth or inspiration of the saying, but only anticipating the thinking and actions of the crowd at Nazareth.