Q. I have a property that I inherited from my parents, it is my sole source of financial support (I’m a single woman, non-employed by health reasons) Due to family issues I’m forced to sell this property at at a loss (less than the true value of the property.) Do I have to give maser (10%) of the sale money obtained? (I always gave maser from monies I earned.)

A. There are different opinions in regards to the origin of giving tithes from monies earned. Rambam (H. Melochim 9: 1) maintains that it was instituted by Yitzchak Avinu. While Ba’al Haturim (Vayetze 28: 22) asserts that Yaakov Avinu originated ma’aser kesafim (tithes given from money earned). Horav Shternbuch Shlit’a in Hochma Vedaas (ibid.) explains that Ya’akov added ma’aser given from capital obtained from an inheritance or received as a gift.
Poskim also disagree if there is a Biblical or a Rabbinical obligation to give ma’aser from monies earned or if it is only a minhag and no obligation at all (Bach Y.D. 249, Sh’vus Yaakov 2:85, Chavos Yoir 224, et. al.)
Horav Shlomo Miller’s Shlit”a opinion is that if someone always gives ma’aser kesofim he has to give also from a yerusha. However, if one finds himself in monetary constraints he would be exempt. (See next question.)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a