Source: Michael Fishbane's Biblical Interpretation in Ancient Israel (New York: Oxford, 1988) 190-191.
Michael Fishbane compares Leviticus 4 and Numbers 15:22-29, which concern unintentional sins. He points out that Leviticus 4 (unlike Numbers 15:22-29) extends its discussion to the high priest who sins, but he still maintains that Numbers 15:22-29 interprets Leviticus 4. One reason seems to be that the Numbers passage is more comprehensive and far-reaching: Numbers 15:22-29 pertains to transgressions of all the commandments, positive and negative, whereas Leviticus 4 mentions only negative commands.
But Leviticus 4 is more specific than Numbers 15:22-29 in that it refers to the high priest's transgressions. Why couldn't it be an interpretation of Numbers 15:22-29? Or why should we even assume one source is dependent on the other? Fishbane acknowledges that there are salient differences between the chapters: Numbers 15:24 mandates a bull and a he-goat for offerings, whereas Leviticus 4 requires a bullock. Maybe they are two separate traditions, which aren't even interacting with each other.
We'll look at Fishbane's treatment of Numbers 15 over the next couple of days.