What does Boxing Day have to do with boxing?

letter of the law

The precise wording rather than the spirit or intent. For example, Since it was the first time he'd broken the rules, the school decided to ignore the letter of the law and just give him a warning. [ Late 1500s ]
The American Heritage® Idioms Dictionary
Cite This Source

Word of the Day

Word Value for letter

Scrabble Words With Friends

Quotes with letter of the law