Bescheidenheit ist eine Zier, doch weiter kommt man ohne ihr

Etymology
Ascribed to. lit. 'modesty/humility is an ornament (i.e. a virtue), but one gets further without it'. The dative case after is now ungrammatical, but used to be fairly common; it is needed here for the rhyme.

Proverb

 * 1) Being modest and humble is a morally commendable approach in life, but it is not usually the most productive in terms of personal success.