This text comes from The Poetical Works of Robert Burns, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
CHORUS.
An O for ane and twenty, Tam!
An hey, sweet ane and twenty, Tam!
I'll learn my kin a rattlin sang,
An I saw ane and twenty, Tam.
They snool me sair, and haud me down,
And gar me look like bluntie, Tam!
But three short years will soon wheel roun',
And then comes ane and twenty, Tam.
And O for ane, &c.
A gleib o' lan', a claut o' gear,
Was left me by my auntie, Tam;
At kith or kin I need na spier,
An I saw ane and twenty, Tam.
An O for ane, &c.
They'll hae me wed a wealthy coof,
Tho' I mysel' hae plenty, Tam;
But hear'st thou, laddie, there's my loof,
I'm thine at ane and twenty, Tam!
An O for ane, &c.