A person may not say to another: “Lend me a kor of wheat and I will pay you at threshing time.” But he may say to him: “Lend me until my son comes,” [or] “until I find the key.” Hillel, however, prohibits [it]. And so Hillel used to say: A woman may not lend another a loaf until she assesses its price, for perhaps wheat will become expensive, and they will come to [a transgression of] interest.

A person may say to another: “Weed with me and I will weed with you,” [or] “Hoe with me and I will hoe with you”; but he may not say to him: “Weed with me and I will hoe with you,” [or] “Hoe with me and I will weed with you.”  All the days of the dry season are alike, [and] all the days of the rainy season are alike. [However] he may not say to him: “Plow with me during the dry season, and I will plow with you during the rainy season.”  Rabban Gamliel says: There is interest paid in advance, and there is interest paid afterward. How? [If] he decided to borrow from him, and he sent to him and said: “[I am doing so] in order that you lend me” —- this is interest paid in advance. [If] he borrowed from him, and returned his money to him, and sent to him, and said: “[This is] because of your money that was lying idle with me” —- this is interest paid afterwards.  R’ Shimon says: There is interest with words —- he may not say to him: “Be informed that so-and-so has come from such and such a place.”

The following transgress a negative commandment: the lender, the borrower, the guarantor, and the witnesses. And the Sages say: Even the scribe. They transgress: You shall not give (Leviticus 25:37), You shall not take from him (Leviticus v. 36), You shall not be to him as a creditor (Exodus 22:24), You shall not impose interest upon him (ibid.), and And before a blind man you shall not place a stumbling block, and you shall fear your God; I am Hashem (Leviticus 19:14).