大方廣佛華嚴經隨疏演義鈔 80.8

80.8

疏「真如之名言含法喻」者，經云「如真如前際不生」等，即以真如喻佛行也。若佛行契如，行即是如，故即是法。

Regarding the commentary’s statement, “The designation ‘tathāgatatā’ (tathatā) contains both doctrine and simile in its phrasing”: the sūtra says, “Just as tathatā is unarisen in the past limit,” and so forth; that is taking tathatā as a simile for the Buddha’s practice. If the Buddha’s practice tallies with tathatā, the practice is itself tathatā, and therefore it is the doctrine.