There is no abundance of learning after abundance of learning, except within the boundaries of learning, and for the world there is much learning.

Hello Rabbi,
The Rama reiterated the rule that ” there is no more learning after more learning, except within the limits of learning, and there is always more learning .”
I did not understand this rule. It appears at the beginning of the article “If Every Living One” (Chapter 1, Chapter 1), and later twice (Chapter 2, Chapter 20 onwards, Chapter 3, Chapter 13 – by implication). This rule is supposed to explain several Sage articles, but I cannot find an explanation for the rule that is used consistently in Sage articles.
If you know of this matter or a source that addresses or explains it and you can direct me to it – I would be happy to.