In this week’s Parsha, ויצא, we are taught how every location is affected by the presence of a צדיק living there. When Yakov left Beer Sheva, the spiritual level of that place was lowered.
The book of Mishlei alludes to not only the contrast between the Tzaddik and the רשע, wicked one, but also to the ישר and the בוגד.
The ישר means that he is straight, or honest. He loves יושר, straightness, and chooses it in every situation. He will suffer any difficulty that he needs to, in order to maintain יושר.
The בוגד, traitor, is the opposite. He does not even know what יושר is and will certainly not admit to it.
The רשע and בוגד tear down their city. The ישר and צדיק strengthen their city.
This is learned from Yakov. Wherever he decided to live, that place became a better place.