淨名經集解關中疏 2.126

2.126

The goddess said: "Spoken words and letters are all the mark of liberation." (Eighth, the goddess explains that inconceivable liberation is identical to letters, in three parts. This is the first, identifying letters with liberation. [Seng]zhao says: "Śāriputra considered words and letters to be a fault and thus remained silent without speaking, thinking that this accorded with true liberation and that he could not yet speak. Silently aligning oneself so that encountering things meets no obstruction—the goddess therefore speaks of equal liberation to awaken his understanding.")