It is pretty much referred to as a "Latin motto"
'I am what you will be, I was what you are now'.
~inscription on the Tomb of James Rice, 15th Century
Sum quod eris, fui quod sis.
I am what you will be, I was what you are.
A reminder inscribed by the ancient Romans on tombstones
Quod Sum Eris
"I am what you will be," a motto for a gravestone
http://ablemedia.com/ctcweb/consortium/ ... toes2.html
"i was what you are, i am what you will be"
http://neuro-mancer.mgh.harvard.edu/zeg ... raphy.html