無疆

Endless; limitless

萬壽 longevity

萬壽無疆

Boundless Longevity

Ten thousand years of boundless longevity 

Wishing a Happy Birthday and many returns

福壽無疆

To have boundless good fortune and longevity

本質

Essence; character; nature; intrinsic quality; essence

vs

現象

phenomenon; appearance