Answer
Lewis acid: $Fe^{3+}$
Lewis base: $H_2O$
Work Step by Step
1. Identify the reactants, and if can act as a base, acid, or both.
$Fe^{3+}$: It is a cation of a highly positive small metal. Therefore it can act only as a Lewis acid.
$H_2O$: Can act as a Lewis base (Lone pairs in the oxygen) or a Lewis acid (Hydrogens that can receive a lone pair to make a bond).
2. Therefore, since $Fe^{3+}$ can act only as an acid, $H_2O$ will have to behave as a Lewis base.
