We consider multi-frequency inverse source problem for the discrete Helmholtz operator on the square lattice Z^d, d \ge 1. We consider this problem for the cases with and without phase information. We prove uniqueness results and present examples of non-uniqueness for this problem for the case of compactly supported source function, and a Lipshitz stability estimate for the phased case is established. Relations with inverse scattering problem for the discrete Schr"{o}dinger operators in the Born approximation are also provided.