A thousand words mean many words. Gu's poem "Yan" says: "A thousand words don't understand, and the warbler crosses the short wall."
A pledge of eternal love is an oath to the mountains and the sea, indicating that the Covenant and oath are as eternal as the mountains and the sea. It also refers to the vows made when men and women fall in love, indicating that love should be as eternal as mountains and seas. Men and women swear to truly love each other and never change their minds. From peach blossom.
Being together day and night means being together all the time. Describe often live together, close relationship. In chapter 14 of Feng Yuxiang's My Life.