Swords Into Inter-Responsibility

Parshat Behukotai 26:37 says “each man before his brother as if from before a sword”. Please note the “as if”. This is analogy for something. For what? Rashi explains that each man will stumble over each other’s sins. We are all responsible for each other:

כל ‘שראל ערבים זה לזה

Shabbat Shalom.