How many times have you seen this?
1.) You must write.
2.) You must finish what you write.
3.) You must refrain from rewriting, except to editorial order.
4.) You must put the work on the market.
5.) You must keep the work on the market until it is sold.
It’s one of those bits of writerly advice that’s quoted ad nauseum, and I’ve always thought that, from #3 on, it was BS. So here’s an article that explains why Heinlein’s advice might get in the way of your ever becoming a good writer, along with the reasons why Heinlein might have set down those rules.