Here is how the song goes:

Lavender’s blue, dilly, dilly,
Lavender’s green,
When I am King, dilly, dilly,
You shall be Queen.

Call up your men, dilly, dilly,
Set them to work,
Some to the plough, dilly, dilly,
some to the cart.

Some to make hay, dilly, dilly,
Some to cut corn,
While you and I, dilly, dilly,
Keep ourselves warm.

Lavender’s green, dilly, dilly,
Lavender’s blue,
If you Love me, dilly, dilly,
I will love you.

Origins:

The first version of this old nursery rhyme came out between 1672 and 1692.
In the 20th century the track got famous for a big audience in the movie “So Dear to My Heart” from Walt Disney in 1949.
According to Wikipedia “the appearance of “Lavender Blue” in the Disney film sparked a revival of interest in the song”.