This quotation is not known to exist in Plato's writings. It apparently first appeared as a quotation attributed to Plato in The Pleasures of Life, Part II by Sir John Lubbock (Macmillan and Company, London and New York), published in 1889.
More quotes by Plato
Oh dear Pan and all the other Gods of this place, grant that I may be beautiful inside.
Wonder is the feeling of a philosopher, and philosophy begins in wonder.
Attribution
Quote text and notes from Wikiquote: Plato (page history), available under CC BY-SA 4.0. Source quality and labels are our own summary of what Wikiquote records.