俱舍論記 15.159

15.159

「論曰至總成四種」者，釋上兩句。說業有四，皆約時定、不定以立四業。時定有三，謂現、生、後，時不定為一。應知不定義有多種，或非定受果故、或非定此時受故、或非定此趣受故、或非定此處受故、或非定受此類果故，如轉重受輕、轉輕受重等，如是等類皆名不定。所以約時辨者，凡論造業於時難定。若於時定，異熟亦定；若於時不定，異熟亦不定，以時離熟無別性故，以時是熟位差別故。

Regarding 'The commentary says, up to making four kinds in total': this explains the first two lines. It says karma has four kinds, all established as four karmas in terms of determinacy and indeterminacy of time. There are three of determinate time, namely present, next birth, and subsequent; and one of indeterminate time. It should be understood that indeterminacy has multiple meanings: either because experiencing the fruit is not determinate; or because experiencing it at this time is not determinate; or because experiencing it in this destiny is not determinate; or because experiencing it in this place is not determinate; or because experiencing this kind of fruit is not determinate, like transforming heavy [karma] to be experienced lightly, or transforming light [karma] to be experienced heavily, and so forth; all such types are called indeterminate. The reason it is distinguished in terms of time is that whenever the creation of karma is discussed, time is difficult to determine. If it is determinate in time, its maturation is also determinate; if it is indeterminate in time, its maturation is also indeterminate, because time has no separate nature apart from maturation, and because time is a distinction of the stages of maturation.