‘The childhood shows the man, As morning shows the day.'- taken from-

This line is taken from John Milton's famous poet Paradise Regained.

John Milton, (born December 9, 1608, London, England—died November 8?, 1674,), English poet, pamphleteer, and historian, considered the most significant English author after William Shakespeare.
Milton is best known for Paradise Lost, widely regarded as the greatest epic poem in English. Together with Paradise Regained and Samson Agonistes, it confirms Milton’s reputation as one of the greatest English poets.
Literary Works:
- Paradise Lost,
- Paradise Regained,
- Samson Agonistes
- L'Allegro,
- Il Penseroso

Source: Britannica.com