Who does good and causes others to do good
ואכלת ושבעת וברכת את-יקוק אלקיך על-הארץ הטבה אשר נתן-לך
You shall eat and be satiated, and [then] bless Hashem, your G-d, for the good land which He has given you
The often-occurring mitzvah of Birkas HaMazon, known colloquially as bentsching, finds its source in the above verse. We are taught that the first three blessings of the four-part bentsching are of biblical origin: to thank Hashem for the nourishment, to thank Hashem for the land, and to thank Hashem for Jerusalem. This is opposed to the final blessing, known as HaTov VeHaMeitiv, literally “the Good and Who causes others to do good”, which is Rabbinic. Why did the Sages enact this extra blessing? They teach us that the reason is in commemoration of the destruction of the city of Beitar.
After the destruction of the second Temple, circa 70 CE, there was one final Jewish stronghold in the land of Israel. It was destroyed during the time of the Bar Kochbah revolt. We are taught that the Roman Caesar Hadrian ordered the destruction of the city, resulting in the death of millions of Jews. For a long time, the deceased weren’t given their rights to a proper burial. Eventually, another Caesar took charge, and allowed for the bodies to be buried. A miracle had occurred, and the bodies never decayed, despite the significant amount of time since their murder. The Rabbis composed and enacted the blessing of HaTov VeHaMeitiv in commemoration of this event. HaTov, He is Good, because the bodies didn’t decay, VeHaMeitiv, He causes others to do good, because the bodies were allowed to be buried.
Another occasion that warrants the blessing of HaTov VeHaMeitiv is when, after a bunch of prerequisites, a person drinks a different bottle of wine than they were before. Instead of making another blessing of Borei Pri HaGafen on the new bottle, they say HaTov VeHaMeitiv. What needs explanation, is why do we make this special blessing on these two occasions? There were many tragedies throughout our history. Why do we specifically commemorate the destruction of Beitar every time we bentsch? If it’s because of the miracle that took place, there also were many miracles throughout our history. As well, what is it about a change of wine that merits its own blessing?
Why don’t we make a special blessing when we have a second, different, loaf of bread? Or other foods? One explanation is that we are taught that there was so much bloodshed in Beitar, that the Romans fertilized their vineyards for seven years with the blood of the Jews. Furthermore, wine resembles blood. This is a historical reason, but is there any other explanation? One that is more intrinsic?
If we examine the entire text of Birkas HaMazon, we’ll see it describes the development of the Jewish nation. There’s a story of a gradual process, guided by Hashem’s oversight. The first blessing of nourishment was originally written in reference to the Heavenly munn the Jews received during their forty years in the wilderness. The munn purified them, making them worthy of receiving the Torah. Hashem took care of their every needs. The second blessing refers to their arrival at the Land of Israel, and the third blessing refers specifically to the building of the city of Jerusalem and the Temple. Hashem’s Presence was apparent there, and there were constant miracles in the city and the Temple.
From a different perspective, the fourth blessing focuses on the unique nation of Israel with regards to its two millennia exile. A wonder of world history, the Jewish people has remained a distinct, Holy, and moral nation, while living scattered throughout the world. After the destruction of the Temple and the subsequent exile, it would have seemed like all hope was lost. The Jewish people surely will intermarry and assimilate into their host nations. Like the ancient Egyptians, Greeks, and Romans, the Jews will make it into the dustbin of history. Everyone looked at Beitar as an example of what’s to come. After the destruction and exile, Beitar was the last stronghold for the Jews in the Land of Israel. Even they failed to maintain their independence, or better yet, their lives. How could the rest of the Jews, who had no independence, maintain their uniqueness, and survive exile?
However, the miracle of Beitar, where the bodies of those murdered didn’t decay, and were allowed burial, shone a ray of hope for those that remained. The Sages saw from that a message from Hashem that indeed, the Jewish people will remain an eternal nation. Hashem is watching over us, and will ensure our survival from those that wish to destroy us. To recall this at all times, they added HaTov VeHaMeitiv to bentsching. Further, another display of the miraculous survival of the Jewish people is from the laws against intermarriage. Drinking the wine of a non-Jew is forbidden, as it could lead to romantic relationships. Refusing to share wine with them should seemingly invoke their distain, even wrath, against the Jewish people. Even so, the Jewish people survived. To commemorate this wonder, the Sages also enacted saying HaTov VeHaMeitiv when drinking a lot of wine.
Let’s try to keep all this in mind when we recite these blessings. Hopefully it will make their words more meaningful. Good Shabbos
 Based on Meshech Chochmah to Deuteronomy 8:10 s.v. ויש להבין
 Deutereonomy loc. cit.
 Berachos 46a and 48b. See the latter, which teaches that Moshe enacted the first blessing, Yehoshua the second, and Dovid and Shlomo the third. See Rashba and Ritva ad. loc. who explain how these blessings can be biblical if they weren’t enacted until after the Torah was given
 See Netzach Yisroel Chapter 7 by the Maharal, who explains at great length the significance of Beitar, its fortitude, and its destruction
 Gittin 57a. See there for the circumstances behind the destruction
 Eichah Rabbah 2:4
 It literally says 800,000,000 people, which is an astonishing number of people, let alone deaths
 Berachos and Eichah Rabbah loc. cit.
 See Shulchan Aruch Orach Chaim § 175
 Berachos 59b
 Although, as ibid 59a and 59b point out, there are other occasions to say HaTov VeHaMeitiv, it will become clear that the blessing on a change of wine is also connected to the destruction of Beitar. See also Mishnah Berurah ad. loc. § 2, who says that too much wine can lead to frivolity, and the words HaTov VeHaMeitiv will remind the drinker of the tragedy of Beitar, and they won’t overdo it. He says that this idea is written in “sefarim”. This appears in the Kitzur Shulchan Aruch 49:8. Ostensibly they’re both coming from Hagahos Rabbi Akiva Eiger ad. loc. § 1, who cites Rabbeinu Bachaye in his Kad HaKemach § 60
 Gittin loc. cit.
 Tosafos to Pesachim 101a s.v. שינוי יין
 Piskei Rosh Berachos 9:15. See there for other explanations
 Berachos 48b. See note 3
 See Mechilta to Exodus 13:17 and Midrash Tanchuma Beshalach § 20: לא ניתנה התורה לדרוש אלא לאוכלי המן
 Avos D’Rabbi Nosson 35:1
 Avos 5:5