黄粱一梦也道不尽你温柔
[huáng liáng yī mèng yĕ dào bù jĭn nĭ wēn róu]
'A fleeting dream can never fully describe your gentleness' refers to the depth and beauty of someone's kindness or tenderness, which is so profound that it seems like just a fleeting dream compared to its reality.