“He will die because of lack of discipline.” The Hebrew word musar (#04148 מוּסָר), normally translated “instruction,” is better translated as “discipline” in this context. In the biblical culture, if a person failed to apply what they had been taught, it was spoken of as if he had not been taught, even though it was through his lack of discipline that he had not applied the learning he had received. However, in our Western way of thinking, we do not say the person was not taught, we say he does not have the discipline to apply the teaching. Thus, although the Hebrew word is “instruction,” in this context we would say “discipline,” as most English versions do. The undisciplined person will also become poor (see commentary on Prov. 21:17).
“abundance.” The Hebrew word is rob (#07230 רֹב), and it means “greatness, abundance, multitude.” In this context, it can mean both “great” in the sense of “huge,” or it can mean “great in number.” The more primary meaning in this context seems to be “abundance,” although the man certainly committed some huge sins—so the man had a lot of sins, and some of them were big sins. The native Hebrew reader would see both meanings and get the full picture.
“go astray.” See commentary on Proverbs 5:19, “going astray.”