Illustrations paragraph 6
Now we will go back to explain what we permitted at the beginning of paragraph 4. If the bridegroom has great deficiencies, there is a distinction. If the deficiency is an illness which the other side does not know of because it is internal, it is obviously not rechilus to reveal this (if all the details are fulfilled).
There is another case where one must reveal the facts – if one heard that the bridegroom is a heretic. Regarding this one can say the Torah writes, Do not go rachil in your nation, right before, Do not stand by your fellow’s blood. But if the deficiency is that the bridegroom doesn’t know much Torah, one does not have to reveal this as the father-in-law caused the loss to himself. He should have got a learned person to test his knowledge of Torah. If not, he accepted the bridegroom as he is.