To err is human, to forgive divine' - Is an example of -

Aphorism:
A terse, memorable expression of a universal truth.

Examples:
'Wives are young men's mistresses; companions for middle age; and old men's nurses.'
 - (Bacon: ''Of Marriage and Single Life'')

'To err is human, to forgive divine.'
 - (Pope: An essay on criticism)

Source: An ABC of English Literature, Dr. M Mofizar Rahman.