Baring-Gould gives a number of variants of this song from around Devon and Cornwall typified by the following:
THE DILLY SONG
Come, and I will sing you. What will you sing me? I will sing you One, O! What is your One, O? One of them is all alone, and ever will remain so.
Come, and I will sing you. What will you sing me? I will sing you Two, O! What is your Two, O? Two of them are lily-white babes, and dress'd all in green, O.
Come, &c. I will sing you Three, O! What is your Three, O? Three of them are strangers, o'er the wide world they are rangers.
Come, &c. I will sing you Four, O! What is your Four, O? Four it is the Dilly Hour, when blooms the Gilly flower.
Come, &c. I will sing you Five, O! What is your Five, O? Five is the Ferryman in the Boat, that doth on the river float, O
Come, &c. I will sing you Six, O! What is your Six, O? Six it is the Dilly Bird, that's never seen, but heard, O!!
Come, &c. I will sing you Seven, O! What is your Seven, O? Seven it is the crown of Heaven, the shining stars be seven, 0!
Come, &c. I will sing you Eight, O! What is your Eight, O? Eight it is the morning break, when all the world's awake, O!
Come, &c. I will sing you Nine, O! What is your Nine, O? Nine it is the pale moonshine, the pale moonlight is nine, O!
Come, &c. I will sing you Ten, O! What is your Ten, O? Ten it doth forbid all sin, from ten begin again, O!
In his notes about the song in 'Songs of the West' he gives the following:
"There are similar verses in German and Flemish; a Scottish version in Chambers' "Popular Rhymes," 1842, p. 50. Also found in Brittany: Luzel, "Chansons Populaires," 1890, p. 88. There is a Medieval Latin form, beginning " Unus est Deus." A Hebrew form is printed in Mendez: "Service for the First Night of the Passover," London, 1862; a Moravian form in Wenzig : "Slavischer Marchen-Schatz," 1857, p. 295. It is also sung in the Eifel, Schmitz : "Sitten u. Brauche des Eifler Volkes," Trier, 1856, p. 113. A Greek form is in Sanders: "Volksleben der Neugriechen." See also : Coussemaker, " Chants populaires des Flamands," Gand, 1850 ; ViIlemarque, Barzas Breis, r8¢6, and later editions."
In these notes he also talks about the variations and about the meaning. In the song manuscripts he gives the texts of most of the collected versions and of several of those referred to above (including the greek one)
Lucy Broadwood also gave a lot of information about interpretation of the song in her the notes on her version of 'Green Grow the Rushes, Oh' in 'English County Songs'