Once upon a time I gave a peirush on Eiqev based upon a Rashi technique used somewhere else - during a speech at another shul.
One fellow in the audience was concerned:
"How can you set aside what Rashi says HERE - in favour of an approach he uses elsewhere"? Meaning Rashi was implicitly disputing my read.
To me the answer is simple, Rashi is NOT exhaustive, meaning here he is giving but an illustrative subset of all the possible p'shatim that even HE would could have given. Therefore do NOT construe from his omission HERE that he objects to something else...
I found a "Proof-Text" for my approach
In Vayeishev 38:26 Rashi gives TWO definitions of "Yassaf" as in «v'lo yassaf od l'daatah»
The second explanation assumes "v'lo Passaq" and relies upon Targum Onkelos found elsewhere re: Eldad and Meidad in B'haalotcha 11:25.
Yet the Local Targum says otherwise! Viz. "V'lo Ossif"
Sh'ma Mina - that Rashi himself felt empowered to quote the Targum elsewhere to bolster his local read of p'shat despite the LOCAL Targum saying otherwise.
And so what I did was the same to employ Rashi to give p'shat in Eiqev from a non-local Rashi despite the local Rashi saying otherwise.
Now it remains possible the local Rashi WAS objecting to the non-local read. We can't know for sure. Nevertheless, it is a legitimate technique to use a non-local source as per Rashi himself