華嚴經探玄記 1.73

1.73

六今總尋名案義，以因果緣起理實法界以為其宗。即大方廣為理實法界，佛華嚴為因果緣起。因果緣起必無自性，無自性故即理實法界。法界理實必無定性，無定性故即成因果緣起。是故此二無二，唯一無礙自在法門，故以為宗。

Sixth, now generally investigating names and examining meanings, we take the dharmadhātu of the true reality of principle in the conditioned arising of cause and effect as its central theme. 'Mahāvaipulya' is the dharmadhātu of the true reality of principle; 'Buddha-avataṃsaka' is the conditioned arising of cause and effect. The conditioned arising of cause and effect necessarily lacks self-nature; lacking self-nature, it is precisely the dharmadhātu of the true reality of principle. The true reality of principle of the dharmadhātu necessarily lacks fixed nature; lacking fixed nature, it forms the conditioned arising of cause and effect. Therefore, these two are not two, but solely one unhindered, sovereign Dharma gate; hence it is taken as the central theme.