Who said "Patience tests but strengthens character."?

This quote is attributed to F.W. de Klerk.

Patience tests but strengthens character. - F.W. de Klerk

"Patience tests but strengthens character."

F.W. de Klerk Patience

President, Apartheid Reformer South African Born 1936 (age 90)

"Negotiation and dialogue are preferable to confrontation and violence."

"Change is inevitable, but the direction of change is not."

"Leadership requires the courage to make difficult decisions."

"Freedom is not given; it must be earned and defended."

"Patience is a virtue I'm still learning."

"I may be a redhead, but I'm not a hothead."

"Patience is a virtue."

"Patience is a virtue I never learned."