Coherent elastic neutrino-nucleus scattering (CEvNS) is calculated to be the dominant neutrino scattering channel for neutrinos of energy $𝐸_𝜈<100  MeV$. We report a limit for this process from data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the pion decay-at-rest neutrino source at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) with $4.2×10^{22}$ protons on target. The dataset provided constraints on beam-related backgrounds critical for future measurements and yielded $<7.4$ candidate CEvNS events which implies a cross section for the process, averaged over the SNS pion decay-at-rest flux, of $<3.4×10^{−39}  cm^2$, a limit within twice the Standard Model prediction. This is the first limit on CEvNS from an argon nucleus and confirms the earlier CsI[Na] nonstandard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon.