Birchat_Hamazon 1

What is the reason for the custom of removing knives from the table before reciting the Grace After Meals? S.H.

The Shibolei Haleket (Chapter 155) tells the story of a man who was reciting Birchat Hamazon, and when he reached the Blessing of “Builder of Jerusalem was so pained that the holy city was in ruins that he took a knife and stabbed himself. (Imagine the passion and awareness this man had when benching!)

The Magen Avraham (Orach Chaim 180:5) rules that we are only concerned at times we can build the Temple. On Shabbat and the Holidays, when it is prohibited to build the Temple, we would not be so concerned, and there is no need to remove knives from the table.

It would seem from his words that we would not have to remove knives when we recite the blessing during the night, when it is also not a time we may build the Temple.