  Geometric Langlands predicts an isomorphism between Whittaker coefficients of
Eisenstein series and functions on the moduli space of $\check{N}$-local
systems. We prove this formula by interpreting Whittaker coefficients of
Eisenstein series as factorization homology and then invoking Beilinson and
Drinfeld's formula for chiral homology of a chiral enveloping algebra.
