Leaned her back against an oak Edinburgh, Edinburgh
Leaned her back against an oak, Stirling for ay

Leaned her back against an oak, first it bent and then it broke
And Bonny St. Johnstone lies fair upon Tay

Leaned her back against a thorn
Two bonniest babes that e'er were born

She took out her milk-white breast
And bid them suck, though it was the last

She took out her little knife
And stabbed away their tender life

Washed the knife all in a brook
The more she washed, the redder it looked

She looks over her father's wall
And sees two babes a-playing at ball

O babes, if you were mine
I'd dress you in the silk so fine

Mother, when we were thine
Around our necks you pulled the twine

Now we're in the heaven so high
And in hell fires you shall die

circa 17th century
The tune is from Songs of the North, Volume 2, a Victorian collection. The words are collated from many versions. From the 'Cruel Mother' family of ballads.