This text comes from The Poetical Works of Robert Burns, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
There's braw braw lads on Yarrow braes,
That wander thro' the blooming heather;
But Yarrow braes nor Ettrick shaws,
Can match the lads o' Galla Water.
But there is ane, a secret ane,
Aboon them a' I lo'e him better;
And I'll be his, and he'll be mine,
The bonie lad o' Galla Water.
Altho' his daddie was nae laird,
And tho' I hae nae meikle tocher;
Yet rich in kindest, truest love,
We'll tent our flocks by Galla Water.
It ne'er was wealth, it ne'er was wealth,
That coft contentment, peace or pleasure;
The bands and bliss o' mutual love,
O that's the chiefest warld's treasure!