While alive the Buddha referred to himself as the Tath?gata, which can mean either "One who has thus come" or "One who has thus gone", and interpreted correctly can be read as "One who has arrived at suchness".

Contents Mahayana Buddhism Tathata in the East Asian Mahayana tradition is seen as representing the base reality and can be used to terminate the use of words. A 5th-century Chinese Mahayana scripture entitled "Awakening of Faith in the Mahayana" describes the concept more fully:

In its very origin suchness is of itself endowed with sublime attributes. It manifests the highest wisdom which shines throughout the world, it has true knowledge and a mind resting simply in its own being. It is eternal, blissful, its own self-being and the purest simplicity; it is invigorating, immutable, free... Because it possesses all these attributes and is deprived of nothing, it is designated both as the Womb of Tathagata and the Dharma Body of Tathagata.

R. H. Robinson, echoing D. T. Suzuki, conveys how the La?k?vat?ra S?tra perceives dharmata through the portal of nyat?: "The Lakavat?ra is always careful to balance nyat? with Tathata, or to insist that when the world is viewed as nya, empty, it is grasped in its suchness."

Chan Budd . . . more

https://en.wikipedia.org/wiki/Tath%C4%81t%C4%81