In my volume of the Pasternak, the poem in the appendix is translated as:
Hamlet
The noise is stilled. I come out on the stage.
Leaning against the door-post
I try to guess from the distant echo
What is to happen in my lifetime.
The darkness of night is aimed at me
Along the sights of a thousand opera-glasses.
Abba, Father, if it be possible,
Let this cup pass from me.
I love your stubborn purpose,
I consent to play my part.
But now a different drama is being acted;
For this once let me be.
Yet the order of the acts is planned
And the end of the way inescapable.
I am alone; all drowns in the Pharisees’ hypocrisy.
To live your life is not as simple as to cross a field.
Did Pasternak use an existing proverb for his poem, or was his novel so popular that one of his own lines became proverbial?
The text has a footnote which explains that 'the last line is a Russian proverb'.