Allusion in Nabokov's Pnin

Question

In chapter 3, section 6 of Nabokov's Pnin, the main character is carrying a reference work "mainly devoted to Tolstoyana" across the Waindell campus when he drops it by accident:

Pnin, on the dirty black ice of the flagged path, slipped again, threw up one arm in an abrupt convulsion, regained his balance, and, with a solitary smile, stooped to pick up Zol. Fond Lit., which lay wide open to a snapshot of a Russian pasture with Lyov Tolstoy trudging across it toward the camera and some long-maned horses behind him, their innocent heads turned toward the photographer too.

V boyu li, v stranstvii, v volnah? In fight, in travel, or in waves? Or on the Waindell campus?

--Page 73 of the Vintage International edition

From which work is the passage in the second paragraph a quotation? (I tried Google, but I suspect the transliteration of the Russian is obscuring the search.) Why would Pnin think of this specific quotation after dropping the book and seeing this photo?

Answer 1

It's from a poem of Pushkin's. An English translation is here. The relevant stanza:

И где мне смерть пошлет судьбина?
В бою ли, в странствии, в волнах?
Или соседняя долина
Мой примет охладелый прах?

And where will fate send death to me?
In battle, in my travels, or on the seas?
Or will the neighbouring valley
Receive my chilled ashes?

Possibly, the quote is brought to mind because Pnin nearly fell over, and he is worried he might have died. But somebody who has read Pnin more recently than I have might have a better explanation of why this quote came to mind.