Lekh Lekha I: Pay attention to those dots!
ונברכו - לשון מבריך ומרכיב, כלומר יתערבו במשפחתך משפחות האדמה, שהרי משקל רפי הוא:
Rashbam, throughout his commentary, reveals the ways in which grammar is a key implement in his toolbox for decoding the text of the Torah. This is one minor example that yields a very different interpretation from the conventional one. All renderings of Bereshit 12:3 assume that the word ונברכו is used here in the sense of blessing, starting with the Septuagint and Onkelos, all the way up to Everett Fox: “All the clains of the soil will find blessing through you!” This is natural in the context of the verse, which talks about blessing and curse.
But a closer look reveals that this reading is somewhat problematic: 1) The verse already covered the notion of blessing and curse, and, if anything, suggested that blessing would flow only to those who blessed Avraham, not to all the nations of the earth! 2) As Rashbam points out, the grammatical form here is passive, what we would call נפעל, as signaled by the lack of a dagesh (dot for emphais) in the bet. Were the verse truly about others receiving blessing through Avraham, then ought it not to have read ויתברכו, as it does in Bereishit 22:18?
Rashbam therefore provides an alternative interpretation: Perhaps the root ברך here is being used in another one of its senses: grafting. [Both blessing and grafting are related to the word ברך (knee); when blessing God, one bends the knee, and grafting reflects the creation of a joint between two parts that resembles a knee. One example of the usage of ברך in the sense of grafting can be found in Mishnah Kilayim 7:1.] God thus promises Avraham that all the clans of the world will be grafted onto his clan, such that his progeny will find itself represented throughout the world. [Interestingly, though not cited by Rashba, there seems to be an antecedent to this approach in the interpretation of this verse offered by R. Elazar on Yevamot 63a.]
Though it is not clear exactly what Rashbam intends by this, it seems that the blessing here is a promise that Avraham’s offspring—if we assume the focus is on Israelites and Jews specifically—will have far-reaching influence and their message for the world will penetrate even the most remote parts of the globe. Perhaps this notion was of some comfort to an exegete living in a small Jewish community in