This text comes from The Poetical Works of Robert Burns, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
The night was still, and o'er the hill
The moon shone on the castle wa';
The mavis sang, while dew-drops hang
Around her, on the castle wa'.
Sae merrily they danced the ring,
Frae eenin' till the cock did craw;
And aye the o'erword o' the spring,
Was Irvine's bairns are bonie a'.