華嚴經內章門等雜孔目章 3.94

3.94

無礙辯才者，謂四十無礙辯。依其十法，十法有四，故成四十。所以說十者，欲顯無量故。如經廣說。

As for unhindered eloquences, they refer to the forty unhindered eloquences. Depending on their ten dharmas, and the ten dharmas having four [aspects], they thus become forty. The reason ten are spoken of is to reveal their immeasurability, as extensively explained in the sūtra.