恋人的灵魂没有一丝白发
[liàn rén de líng hún méi yŏu yī sī bái fā]
The meaning is 'Lovers' souls don't have a single white hair.' In the Chinese context, 'no white hair' means they never age or get old together, so it indicates a pure and everlasting love between two lovers, emphasizing that it hasn't been troubled by the vicissitudes of life.