青青子衿,悠悠我心。
Green, green is your collar; long, long is the yearning in my heart.
Plain meaningYou stay on my mind, and my longing does not fade.
The Book of Songs
Original context and translation note
The collar identifies the person being longed for; the repeated words make the feeling linger.
English wording on Gu Ren Said is an original reading aid, not a claim that there is only one valid literary translation.