What is the origin of the term/word LAY' as it applies to payment of nantucket whalers? Thank you.?

I'm familiar with the term from "In the Heart of the Sea," but I'm coming up empty on its etymology.

A lay is a share of the profits. Melville's first voyage, I read in trying to answer this question, paid a lay of 1/175. The more seasoned or higher in the chain of command a man was, the larger his lay. A captain of a whaling ship might earn 1/8 lay.

Could you post the sentence in context? As a nautical term, lay has several uses:

[Lay:    To come and go, used in giving orders to the crew, such as "lay forward" or "lay aloft". To direct the course of vessel. Also, to twist the strands of a rope together. To make it to a mark, buoy, or harbor, such as "We will lay the mark".]