I agree with Helen and Sheila: "ashrei" as in the prayer "ahrey ha'ish" (which Hannah Szenes probably knew) means happy/fortunate. "Blessed" is a drift from the primary meaning which, ever so slightly, places the origin of the happiness in someone else's hand, the one who is "blessing", or at least suggests a reward. The poem proposes no other reward than the very fact of doing the right thing, should we be blessed for it afterwards or not.
I agree with Helen and Sheila: "ashrei" as in the prayer "ahrey ha'ish" (which Hannah Szenes probably knew) means happy/fortunate. "Blessed" is a drift from the primary meaning which, ever so slightly, places the origin of the happiness in someone else's hand, the one who is "blessing", or at least suggests a reward. The poem proposes no other reward than the very fact of doing the right thing, should we be blessed for it afterwards or not.