華嚴經金師子章註 1.118

1.118

若兩處看，俱顯俱顯，隱則祕密，顯則顯著，故名祕密隱顯俱成門。

If one looks from both standpoints, both are manifest and both are concealed: being concealed, they are secret; being manifest, they are evident. Therefore it is called the gate of the secret simultaneous establishment of the hidden and the manifest.