הלכה אויף שמות 40:38

A God-fearing man shall not reside in a place where people are suspect of (breaking) bans and vows. Each transgression is remedied by repentance, but when involving the ban and vow repentance will not cleanse him in this world.¹Yoma 86a. It is, therefore, not good to reside with them for it is impossible that he should not derive profit from them or give profit to them. All who transgress the ban are regarded as if they transgressed the Five Books of the Law.²Sanhedrin 44a. And if you count each word at the end of each book, “In Egypt,” of the book of Genesis; “Their journies,” of the book of Exodus; “Sinai,” of the book of Leviticus; “Jericho,” of the book Numbers; “Israel,” of the book of Deuteronomy; and take the first letter and the last of each and every word they will total the word “ban” ³The letters, when added together, total 248. and “ban” has the numerical value of 248, corresponding to the number of membrums in a person.⁴Bekhoroth 45a.