Question: Is one obligated to recite Birkat Hamazon specifically where one has eaten bread or may one recite this blessing elsewhere?
Answer: One who eats a bread meal must recite Birkat Hamazon in the place where one has eaten and one may not go to a different place and recite the blessing there. Only after one has recited Birkat Hamazon in the original place one has eaten may one continue on to another place.
If One Moves to Another Place
We must now discuss the law of an individual who leaves the original place where he has eaten and moves to another place: Will this individual be required to return to the original place where he has eaten or will he be permitted to recite Birkat Hamazon in the new place he has gone to?
This actually depends: If one intentionally left the original place one has eaten, one must return to that place in order to recite Birkat Hamazon and one may not recite it in the place one currently finds himself.
However, if this was done unintentionally, i.e. if one had forgotten to recite Birkat Hamazon, moves to another place, and only later remembers that one must recite Birkat Hamazon, the Rishonim disagree whether or not one must return to the original place where one has eaten in order to recite Birkat Hamazon. Maran Ha’Shulchan Aruch (beginning of Chapter 184) writes: “If one unintentionally leaves one’s original place, according to the Rambam, one may recite Birkat Hamazon in the place one remembers to do so; according to Rabbeinu Yonah and the Rosh, however, one must return to one’s original place in order to bless.”
The Poskim are unsure whether Maran intends to rule in accordance with the view of the Rambam and one who moves unintentionally need not return to one’s original location in order to recite Birkat Hamazon or if Maran indeed intents to rule in accordance with the opinion of Rabbeinu Yonah and the Rosh that even if this was unintentional, one must nevertheless return to his previous place.
Maran Rabbeinu Ovadia Yosef zt”l writes that Maran indeed intended to rule in accordance with the view of the Rambam as opposed to the opinion of Rabbeinu Yonah and the Rosh who are a lone opinion on this matter. Thus, halachically speaking, one need not return to one’s original place in order to recite Birkat Hamazon. Besides for the fact that the opinion of the Rambam is agreed upon by a majority of the Poskim, we must add the fact that Maran Ha’Shulchan Aruch based his halachic work for the most part on the rulings of the Rambam, as Maran himself states in his Responsa Avkat Rochel that the Rambam was the greatest of Poskim whom all communities in Israel, the Middle East, and North Africa accepted as their rabbi and followed his every word.
Thus, the letter of the law dictates that one who unintentionally leaves the place where one has eaten without reciting Birkat Hamazon and later remembers that one must recite Birkat Hamazon may recite Birkat Hamazon wherever one is when one remembers, in accordance with the ruling of the Rambam. However, if one acts stringently and returns to one’s original place in order to recite Birkat Hamazon in accordance with the opinion of the Rosh, this is certainly praiseworthy.
Summary: One must recite Birkat Hamazon in the place where one has eaten one’s meal. If one intentionally leaves the place where one has eaten without reciting Birkat Hamazon, one must return to one’s original place in order to bless. However, if one leaves one’s original place unintentionally, according to the letter of the law, one need not return to one’s original place in order to recite Birkat Hamazon; however, if one does so, one shall surely be blessed from Above.
