  Cusp forms are certain holomorphic functions defined on the upper half-plane,
and the space of cusp forms for the principal congruence subgroup $\Gamma(p)$,
$p$ a prime, is acted by $\mathrm{SL}_2(\mathbb{F}_p)$. Meanwhile, there is a
finite field incarnation of the upper half-plane, the Deligne--Lusztig (or
Drinfeld) curve, whose cohomology space is also acted by
$\mathrm{SL}_2(\mathbb{F}_p)$. In this note we compute the relation between
these two spaces in the weight $2$ case.
