Q. Someone has a close friend that was his neighbour and went to school together with from early youth. He knows that his friend as a child had a cancerous tumour that although it was removed, yet he knows that it could return.
The friend became recently engaged to another family that he also knows. Yet, he does not think they are aware of the health problems that his friend suffered with as a child and may return. Is he obliged to tell them?

A. Sifra (Vayikra 19: 14) explains that the prohibition of ‘Don’t place a stumbling block in front of the blind,’ includes telling one about to get married wrong information that could be detrimental in the future.

Chofetz Chaim (p.233) rules that it includes also not informing of existing prejudicial conditions on one about to be wed to an affected partner. However, he mentions most important conditions to be met.

Horav Shlomo Miller’s Shlit’a opinion is that in our particular case is that if the projected natural life expectancy of the one to be married at that age would be ‘x’ years predicted by by a certain percentage and the added risk would diminish
it by an equal percentage, he must inform the future partner.

Rabbi A. Bartfeld as revised by, Horav Dovid Pam, Horav Aharon Miller, Horav Chanoch Ehrentreu and Horav Kalman Ochs Shlit’a