白首成约
[bái shŏu chéng yuē]
Grow old with you under oath. Some wish the loved ones keep company until the death do them apart, indicating loyalty and commitment. It is not a light decision but an expression of longing, hoping to have someone stay and support when growing up and getting old gradually, experiencing the change together and witnessing all the ups and downs with each other throughout years of life, no separation by distance, war or poverty.