君誓伴妾三生不离妾誓随君三生不弃
[jūn shì bàn qiè sān shēng bù lí qiè shì suí jūn sān shēng bù qì]
It implies 'You vow to stay with me for three lives without parting; I vow to follow you for three lives never to give up'. In ancient China, people believed they might reincarnate for more than one life. Hence this expresses deep vows of loyalty and eternal love between two people.