Giving Ma'aser for the Past and Returning More than One Borrowed

Dear Rabbi, I have a few questions regarding masser and ribit, and I would greatly appreciate your guidance. I didn't know that one needs to pay masser on tax refunds and other government benefits. Since I learned that, I have been giving maaser. My question is, what should I do about the past? I borrowed a tissue box and returned a bigger size box. Is there a question of ribit in such a situation? My boss paid me late and mistakenly gave me a little less. I didn't say anything and forgave him for it. Is there a question of ribit here? Thank you for helping me be a better Jew.

Shalom!

Thank you for your question.

Your commitment to donating ma’aser is very commendable.

Let’s take a look at the ma’aser enactment.

According to some authorities, giving ma’aser is a Torah obligation. The basis for this opinion is taken from the episode where Yakov was forced to flee from his brother Esav who threatened to kill him. While on the run, he camped for the night to go to sleep at which time he had his famous dream of the ladder extending to heaven. Upon awakening from the dream Yakov promised God that he will donate ten percent of his wealth to charity in exchange for God’s protection. Some also point to Avraham Avinu as the source for giving ma’aser as Avraham gave Malchitzedek a ma’aser gift.

Most other authorities, however, rule that giving ma’aser is a rabbinical enactment and that the episode of Yakov was not intended to serve as a literal binding ma’aser enactment. It’s simply an “asmachta” a source of inspiration for this commendable practice.

Yet other authorities insist that giving ma’aser is no more than a custom or "middat chassidut," or even just “good advice.” According to this approach, giving ma’aser is very commendable though there is no true obligation to do so.

On the topic of making up “missed” ma’aser donations: if one never took ma’aser in the past and one is now taking on this commendable practice then one need not worry about past “missed” contributions. But one who was in the habit of giving ma’aser and then had a lapse of contributing should slowly pay back, little by little.

Regarding your question of borrowing a tissue box and returning a bigger size box: while one should endeavor to be exacting where possible, if the size of the box was not significantly larger than the first box it is fine there is nothing to worry about.

Regarding your boss paying you too little, too late: this not a ribbis issue, but rather a different issue beyond the scope of this response. You should discuss it with him and ask him to be more exact in this area.

Ma'aser Sources: 

Sources: Tosfos, Taanis 9a; Taz, YD 331:2; Pischei Teshuva, YD 331:12; Chavos Yair 224; Maharil 54; Teshuvos M’ahava 1:87; Aruch Hashulchan, YD 249:2,5; Birkei Yosef, YD 249:3; Sheilas Yaavetz 1:6; Chasam Sofer, YD 331; Ahavas Chessed 2:18:2

Ribbis Sources:

Bris Yehuda 17 footnote 6; Toras Haribis 7:7; Avnei Nezer, CM 23.