4. As shown in Figure 1, points $B$ and $E$ are on the sides $AD$ and $AC$ of $\triangle ACD$, respectively. $BC$ intersects $DE$ at point $F$. Given that $\triangle ABC$ and $\triangle AED$ are congruent, $AB = AE = 1$, and $AC = AD = 3$. Then the ratio of $S_{\text{quadrilateral } ABFE}$ to $S_{\triangle MDC}$ is $\qquad$
4. $\frac{1}{6}$.

Notice that
$$
S_{\triangle A B F}=S_{\triangle A B F}=\frac{1}{2} h, S_{\triangle A D F}=\frac{3}{2} h .
$$

Therefore, $S_{\text {quadrilateral } A B F E}=h, S_{\triangle D C}=3 S_{\triangle A D E}=6 h$. Thus, the required ratio is $\frac{1}{6}$.