Shulchan Aruch of Rabbi Shneur Zalman of Liadi, Volume 12: Choshen Mishpat

It is forbidden for a person to sell a colleague land or movable property over which there is a legal dispute or a pending suit by another person unless he notifies the purchaser.

saying something that indirectly leads to the recognition of a colleague’s failings. For example, if a question regarding an intellectual concept was raised, one should not ask a person who is not familiar with that field of knowledge: “How would you answer this question?” “What is your opinion about this matter?” or the like.135

Iyov was claiming that Divine retribution was being visited upon him without cause. His friends challenged that assumption, implying that he was worthy of punishment.

“Acquire this for so-and-so.”37 [As a result,] when he receives it, he acquires it on the other person’s behalf; it is as if that person had personally received it, because a benefit can be acquired for a person even when he is not present.38

Nevertheless, [the lender] must return every implement [taken as security] to the borrower when he requires it and come back and take it when he does not require it.76

One should not send a friend a barrel of wine with a layer of oil floating on top of it, for the recipient will think that the entire barrel contains oil.84 He [might] then invite guests to partake of it, confident that he has an abundance of oil for their needs and then he will suffer embarrassment.

Even if [the borrower does not offer] security, one is obligated to lend to him, and even give him a free gift,10

“truth in advertising.” While it is considered unfair and forbidden to lead someone to a mistaken conclusion, there is no difficulty if he arrives at that conclusion on his own without having been misled.

Similarly, he should not ask a colleague: “How much do want to sell this object for?” when he does not desire to buy it or he does not have the financial resources to do so, and his intent, instead, is to deceive his colleague.127 Afterwards, when he does not purchase it, his colleague will realize that he intended to deceive him and it will distre