A traditional nursery rhyme for children, from 1680. 

See a more modern version of this song: Lavender (by The Wiggles) 

Lavender's blue, diddle diddle, lavender's green,
when I am king, diddle diddle, you shall be queen.

Call up your men, diddle diddle, set them to work
Some to the plough, diddle diddle, some to the pond.

Some to make hay, diddle diddle, some to cut corn.
While you and I, diddle diddle, keep ourselves warm.

(x2)