The word 鬻 (yù) appears to originate as a joint pictogram from:
- 粥 depicting the rice and two whirls of steam on the sides
- 鬲 (pronounced lì?) a cooking vessel
Later 粥 alone came in use to express the original meaning (congee), and 鬻 became a loan for "to sell". The loan is reported in the Zhuangzi 庄子.
However I've always known that the actual meaning of this word is "to sell poetry for a living", which is basically the translation of the idiom 鬻文为生. This idiom is also the only sentence where I ever heard the character 鬻 (heard, yes, I actually heard someone uttering this). The dictionaries I checked report only 卖 as a synonym, and other usages consistent with "selling", but the offered examples all gravitate toward "selling art" as 鬻画, 鬻哥 where it looks like a separable verb.
Given the highly specific collocations, I wonder if there is a story behind the etymology of the word, e.g. the same way there is a story behind a chengyu like 画蛇添足。I couldn't find any so far.