Birkat Hamazon - The Blessing(s) After a Meal
We are taught, “He (G-d) gives bread (sustenance) to all mankind, for His kindness is forever.” (Tehillim 136:25)
My five-year-old son and I were travelling on the train on a particularly hot summer day. We both noticed a family making a dash to make it onto the train. Once seated, the children were given some soda to drink to help them cool off. Each one guzzled down his drink, returning his empty cup for a refill. My son and I couldn’t help notice that they weren’t making berachot. I explained to my son that not everyone makes blessings when they eat and drink.
While other blessings for food are Rabbinical in nature, it is a positive mitzvah from the Torah to recite “birkat hamazon”. This is comprised of three berachot that are “Torah berachot”, and a fourth, “Rabbinical beracha”. They are said after one eats a sustaining meal that includes bread, as it is written, “You shall eat and be satiated, and you shall bless the L-rd your
There is a general rule regarding after-blessings: Since blessings said after food in general are only a Rabbinical requirement, when there is a doubt regarding a blessing, one is lenient and does not recite it (Aruch Hashulchan Orach Chaim 7:5). Accordingly, if one is not sure if he recited birkat hamazon on a kezait of bread, he does not recite it (again). When one has eaten bread and is satiated, then his requirement to recite birkat hamazon is mandated by the Torah. In this case, if he is in doubt he must be strict and recite birkat hamazon. This is in accordance with the rule that when there is a doubt regarding a Biblical obligation one must be strict. (Shulchan Aruch Orach Chaim 184:4; Mishnah Berurah 184:15)
Therefore, in a situation of doubt, one says only the first three blessings of birkat hamazon. This is because only the first three blessings are a Biblical requirement. The fourth blessing was instituted by the Rabbis in the Talmudic era (Rambam) and is a Rabbinical requirement (Ben Ish Chai, Laws of Birkat Hamazon 9).