Quotes from the Buddha Treasury Sutra,

Vol. 1

“Śāriputra said to the Buddha, ‘World-Honored One! Each time I am in a retreat, I ponder, “The World-Honored One uses terms to speak of the Dharma indescribable by terms, and uses language to speak of the Dharma indescribable by language.” Thinking of this brings forth the thought of rarity.’”

The Buddha imparted to Sariputra: ‘Indeed, indeed! This rarity is utterly so, it is unequaled so, this is showing the Anuttara-samyak-sambhodi of all Buddhas. Sariputra! Such as the skillful artisan, who draws in the empty space and manifests various different forms. How do you say? Is what this artisan does a rarity?’”

“A rarity. Your World-Veneration!”

“Śāriputra! The Anuttara-Samyak-Sambodhi attained by the Tathagata teaches that all dharmas are neither arising nor ceasing, signless, and unconditioned. If people believe in and understand this, it is doubly rare. Why is this so? This Dharma, indescribable by terms, has no thought and no gain and does not cultivate. It is inconceivable and does not rely on the mind. It has no conceptual elaborations and cannot be relied upon by conceptual elaborations.”

《佛藏經》卷上

「舍利弗白佛言：「世尊！我在靜處每作是念：『世尊乃於無名相法以名相說，無語言法以語言說。』思惟是事生希有心。」

佛告舍利弗：「如是，如是！是事希有、第一希有，謂是諸佛阿耨多羅三藐三菩提。舍利弗！譬如巧畫師，畫於虛空現種種色相。於意云何？是畫師者為希有不？」

「希有。世尊！」

「舍利弗！如來所得阿耨多羅三藐三菩提，說一切法無生無滅、無相無為，令人信解，倍為希有。所以者何？無名相法、無念無得亦無有修，不可思議、非心所依、無有戲論，非是戲論所可依止。」