The table below presents presents two contradictory verses/verselets. Both verses/verselets talk about God's attributes on dealing with sinners. The underlined words highlight the contradiction. One verse/verselet says God cleans sins while the other verse says God doesn't clean sins. Which is it? Does God clean sins or not? Rashi simply resolves this using the two aspects method: God cleans sins when people repent. But if people don't repent and the children continue their parents behavior God doesn't clean sins but visits the sins on both parents and children.

Summary	Verse / Source	Text of verse / Source
God cleans sin	Nu14-10	God, [you are] long suffering and very merciful, you lift sin and iniquity; [although] you clean [sin] you [sometimes] don't clean [sin] [namely when you can] visit the sins of parents on their children [because the children uphold their parents sin]
God doesn't clean sins	Nu14-10	God, [you are] long suffering and very merciful, you lift sin and iniquity; [although] you clean [sin] you [sometimes] don't clean [sin] [namely when you can] visit the sins of parents on their children [because the children uphold their parents sin]
Resolution:	2 Aspects	God cleans sins when people repent. But if people don't repent and the children continue their parents behavior God doesn't clean sins but visits the sins on both parents and children.

Advanced Rashi: Note especially how this Rashi can give rise to a flowing translation of the verse. In the above table our suggested flowing translation is indicated by the bracketed words. I believe that the form X not X as in cleans doesn't clean should be interpreted as a Biblical idiomatic style requiring the above-indicated bracketed expressions.