This sentence usually appeared in literary works, meaning that marriage transformed love into kinship, making love dull, estranged, and eventually dying. In novels, marriage is often seen as the grave of love because it marks the transformation of love into more realistic and practical social relationships, including family responsibilities, property disputes, child support, and so on. This shift could weaken the romance and passion of love and make it fade away. However, this sentence can also be understood as marriage is the ultimate form of love. Only in marriage can love be preserved and reflected forever. Therefore, it could also be seen as an affirmation and praise for love.