Who does good and causes others to do good[1]
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[2]
The often-occurring mitzvah of Birkas HaMazon, known colloquially as bentsching, finds its source in the above verse. We are taught[3] 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[4] that the reason is in commemoration of the destruction of the city of Beitar.