This text comes from The Poetical Works of Robert Burns, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
Now bank an' brae are claith'd in green,
An' scatter'd cowslips sweetly spring,
By Girvan's fairy haunted stream
The birdies flit on wanton wing.
To Cassillis' banks when e'ening fa's,
There wi' my Mary let me flee,
There catch her ilka glance o' love,
The bonie blink o' Mary's ee!
The chield wha boasts o' warld's wealth,
Is aften laird o' meikle care;
But Mary she is a' my ain,
Ah, fortune canna gie me mair!
Then let me range by Cassillis' banks
Wi' her the lassie dear to me,
And catch her ilka glance o' love,
The bonie blink o' Mary's ee!