If we have a statement of the form $P \implies Q$ and this statement is true, then we say that $P$ is a sufficient condition for Q.
Suppose the following statement:
$$2 \, \text{is odd} \implies I \, \text{is invertible}, \qquad \text{where $I$ is the identity matrix}$$
The above material conditional is True just because $P$ is False or $Q$ is True. But there isn't anything that allows to guarantee (sufficient) $Q$ from $P$. Why in such cases we call $P$ a sufficient condition for $Q$?