Birkat Hamazon: Blessing for Host

Why does Birkat Hamazon include a prayer for the host.

Shalom! 

Thank you for your question. 

A guest is required to bless his host after eating a meal as part of the Birkat Hamazon. This requirement is derived from the same verse that requires us to recite Birkat Hamazon: “V’achalta v’savata u’verachta et Hashem Elokecha…” It is explained that, in addition to having to bless God after eating a meal, the word “et” teaches us that one must also bless the host who provided the meal. 

There is a widespread practice to only recite a brief blessing for a host even though the Talmud mandates a lengthier blessing. Most authorities frown on this practice and strongly urge one to recite the version that appears in the Talmud which is actually a combination of different versions of the prayer that were written by different sages. The host should answer “amen” after a guest blesses him. 

Every guest should recite the blessing for the host regardless of how many guests are present. When there is more than one host, the blessing should be recited in the plural. A guest should not decline the honor of leading Birkat Hamazon. One who pays for his meal is not considered to be a guest and is not truly required to bless the host. One may bless the host even if he is not present. 

 OC 201 with commentaries; Sefer Hamanhig, Seuda 15; Rokei’ach 315; Smag 27; Machzor Vitri 53; Abudraham, Birkat Hamazon