Be patience, honesty, simplicity, etc. itself
Definition 1 of 1
Pro Tip 1/3Metaphorical Use
This phrase is used metaphorically to compare a person to the essence of these virtues. 
My grandmother is patience itself, always so calm in any situation.
Pro Tip 2/3Figurative Expression
The expression is not literal but highlights that someone has a remarkable quality. 
During the crisis, the leader was honesty itself, being open about the challenges faced.
Pro Tip 3/3Cultural Imagination
This phrase taps into the cultural ideal that certain virtues are highly valued and respected. 
He is simplicity itself, living a life free from the traps of modern consumerism.