Behar- Bechukotai

And if you sell something to your neighbor, or buy something from your neighbor’s hand, you shall not wrong one another. According to the number of years after the Jubilee year you shall buy of your neighbor, and according to the number of years of the fruits he shall sell to you, according to the number of years you shall increase its price, and according to the fewness of years you shall diminish the price…you shall not wrong one another, but you shall fear your God for I am the Lord your God.

25:14 – 17

The “wrong” of verse 14 refers to overcharging. The “wrong” of verse 17 refers to vexing by words. When you sell or buy real estate, take into account how many years there are until the Jubilee, and according to the years and yield expected from the field, shall the vendor sell and the purchaser buy, for eventually the purchaser must return it to the vendor in the Jubilee year…It must therefore be purchased according to the relevant period.

Rashi (13^th Century)

What is vexing by words? One must not say to a repentant sinner: Remember your former deeds; to a descendant of a convert one must not say: Do not forget the conduct of your forefathers…One must not say to an ill person afflicted with pain or one who buries his children…”Recall now who that was innocent, ever perished or where were the upright cut off? Donkey drivers who seek fodder for their animals must not be sent to someone who has never traded in animal rations. Rav Yishmael says: Nor may one haggle over a price when one has no money. This is a matter of conscience, and in all such matters the Torah warns, “you shall fear your God.”

Bava Metzia 58b (7^th Century)

Nothing should be said to an Israelite that may hurt or grieve him and leave him frustrated…Since it is impossible to list all the examples, everyone must be on guard, for God knows mans’ every thought and intention. Man only sees into his fellow’s eyes, but God looks into the heart…The commandment however, would not require us to remain silent when annoyed, for no one is made of iron…Rather, we must refrain from reviling and initiating quarrels. Thus one can avoid being offended, for only the mindless would revile an amicable person, and these can be ignored. When compelled to react to insults, the intelligent will do so gently and without anger…

Sefer Hachinuch (16^th Century)

The 7^th year and Jubilee introduce the concept of God into all the business transactions of man, and make it clear that all men live and work together on the one soil of God…The obvious corollary to this idea; that is, that all of communal life takes place before the eye of God, is that God is present not only in the Temple but also in the midst of all business and commerce transacted by the members of the nation…

Samson Raphael Hirsch (20^th Century)

In any sale it is forbidden to disadvantage the seller or the purchaser. For instance, the seller must not skim off any dust particles from the top of the drawer to create the impression that the purchaser receives completely refined merchandise none of which turns out to be substandard or useless.

Sforno (15^th Century)