执了我手必定白头牵着我走必定一生
[zhí le wŏ shŏu bì dìng bái tóu qiān zhe wŏ zŏu bì dìng yī shēng]
This can be translated as 'Holding my hand will lead to a white-haired old age; walking together surely means all of life'. It signifies a lifelong partnership and undying love between two people who stay together through thick and thin until their hair turns white from old age.