We let the dangling Berachah dangle for now. Don't worry, it will fall into its place. First, I would like to discuss another editor. Consider the passage Shemot 4:24-26:
It was on the way, in a lodging place, that Hashem encountered him and sought to kill him. So Zipporah took a sharp stone and cut off the foreskin of her son and touched it to his feet; and she said, "You caused my bridegroom's bloodshed!" So he released him; then she said, "A bridegroom's bloodshed was because of circumcision."
This is very strange indeed. The excessive use of pronouns, with no antecedents, suggest that the passage is not in its proper context. Looking for the proper context, there is only one candidate. It must be after Shemot 2:21-22:
Moses desired to dwell with the man; and he gave his daughter Zipporah to Moses. She gave birth to a son and he named him Gershom, for he said, "I have been a stranger in a foreign land."
and before the phrase "And it was after many days". Therefore, it must be right after "Shemot 2:21-22", yielding:
Moses desired to dwell with the man; and he gave his daughter Zipporah to Moses. She gave birth to a son and he named him Gershom, for he said, "I have been a stranger in a foreign land." It was there, in the land of Midian, that Zipporah took a sharp stone and cut off the foreskin of her son and touched it to his feet; and she said, "You are being a bloodshed to Me!" And Hashem encountered him and sought to kill him, and He released him; then she said, "A bridegroom's bloodshed was because of circumcision."
In this passage, the antecedent of the pronouns in "It was on the way, in a lodging place, that Hashem encountered him and sought to kill him" must be Gershom, the latest person mentioned by name.
As for the editor that created the split, we must suspect that who added P to the Torah, wanted to enhance "his" Bereshit 17, the competing passage of the Brit Milah. By splitting the paragraph, and so introducing many problems of interpretation, the J-passage of the Brit Milah is automatically demoted. And, in the eyes of the editor, Avraham would surely be a better mohel than Zipporah, for the generations. And, for the generations, would the Brit of Abraham not seem to be more elevated than the Brit of Zipporah? But know the truth: the Brit of Zipporah, the Brit of "foreskin for life," of Chatan Damim, is the (much) older one.
The phrase "It was on the way, in a lodging place", was changed to "It was there, in the land of Midian", וַיְהִי שָׁם, בְּאֶרֶץ-מִדְיָן in Hebrew. Mutatis Mutandis, and Gershom was named also after the Brit Milah.
