Long John Silver, "you may lay to that"

Question

In Robert Louis Stevenson's Treasure Island, the "ambiguous rogue" (I saw this phrase somewhere and it's my favourite description of the character) Long John Silver frequently uses the phrase "you may lay to that", essentially meaning "you may be sure of that". I'm interested in the implications and history of this phrase. This forum thread has several competing claims: that "lay to" is a nautical phrase related to laying anchor; that it refers to laying down money as in betting; that Stevenson invented the phrase; that it was an old phrase before Treasure Island. Probably Stack Exchange can do better at laying (ha) out the correct information clearly and backing it up with proper evidence.

• What does the phrase "you may lay to that" refer to - laying anchor or laying money (or neither)?
• What is the origin of the phrase - invented by Stevenson or much older, a nautical term or in general usage?
• Does Long John Silver's use of this phrase (he really uses it a lot) indicate anything about his character?

Answer 1

“Lay” has meant “put down or deposit as a bet, wager” since the 13th century. The earliest citation in the OED is from Floris and Blancheflour:

Ȝerne he wule þe bidde and preie
Þat þu legge þe cupe to pleie.†

_{J. Rawson Lumpy & George H. McKnight, eds. (1901). King Horn, Floriz and Blauncheflur, the Assumption of Our Lady, p. 93. London: Early English Text Society.}

_{† “Yearn he will thee bid and pray that thou lay the cup to play”, that is, he wishes to ask you to wager the cup (presumably an ornamental and valuable vessel).}

However, it seems that Stevenson originated “lay to” in the sense “bet on”. Prior to the 1883 publication of Treasure Island, the OED records “lay [a wager]”, “lay for”, “lay upon” and “lay against”, but not “lay to”.

We can only speculate about why Stevenson adopted this form of words. It may have been a deliberately faux-antique turn of phrase, to give the character a distinctive idiolect; it may have been a pecularity of speech of the “admired friend of mine” on which Stevenson based the character (Essays in the Art of Writing, p. 119); or it may have been a happy error, perhaps influenced by other senses of “lay” (impute, assign, ascribe, etc.) which do take “to”. I’m inclined to prefer the first of these explanations, as the phrase seems to have stuck with many readers, for example:

It will be long before John Silver loses his place in sea fiction—“and you may lay to that.”

_{Arthur Conan Doyle (1890). ‘Mr. Stevenson’s Methods in Fiction’. In Littell’s Living Age 2381, 15 February 1890, p. 420.}