Lammas

From "The Battle of Otterbourne", collected in "The Minstrelsy of the Scottish Border".

It fell about the Lammas tide,

When yeomen win their hay,
The dochty Douglas 'gan to ride,
In England to take a prey.'"
...
" Out then spoke a bonny boy,
That serv'd ane o' Earl Douglas' kin—
' Methinks I see an English host,
A coming branking us upon.'

" ' If this be true, thou little foot page,
If this be true thou tells to me,
The brawest bower in Otterbourne
Shall be thy morning's fee.

" ' But if it be false, thou little boy !
But and a lie thou tells to me,
On the highest tree in Otterbourne,
Wi' my ain hands, I'll hang the hie! '
'' The boy has ta'en out his little penknife,
That hung right low down by his gare,
And he gave Lord Douglas a deadly wound,
I wot a deep wound and a sare.

" Earl Douglas to the Montgomery said,
' Take thou the vanguard of the three ;
And bury me by the braken bush,
That grows upon yon lilye lee.'"
 
Lammas, or loaf-mass day, occurs on August 1st, and is one of the four main pagan festivals of the year.  The Gule of August, as the day is also known was practiced in Lothian into the middle of the eighteenth century, a generation before Scott was born.
 
From the Book of Days, this description of Lammas Day activities: From the unenclosed state of the country, the tending of cattle then employed a great number of hands, and the cow-boys, being more than half idle, were much disposed to unite in seeking and creating amusement. In each little district, a group of them built, against Lammas-day, a tower of stones and sods in some conspicuous place. On Lammas-morning, they assembled here, bearing flags, and blowing cow-horns—breakfasted together on bread and cheese, or other provisions—then set out on a march or procession, which usually ended in a foot-race for some trifling prize. The most remarkable feature of these rustic fetes was a practice of each party trying, before or on the day, to demolish the sod fortalice of some other party near by. This, of course, led to great fights and brawls, in which blood was occasionally spilt.