Śrīmālādevī Siṃhanāda Sūtra

The Śrīmālādevī Siṃhanāda Sūtra (traditional Chinese: 勝鬘師子吼一乘大方便方廣經, Lion’s Roar of Queen Śrīmālā) is one of the main early Mahāyāna Buddhist texts belonging to the Tathāgatagarbha sūtras that teaches the doctrines of Buddha-nature and "One Vehicle" through the words of the Indian queen Śrīmālā. After its composition, this text became the primary scriptural advocate in India for the universal potentiality of Buddhahood.

Source: Wikipedia — Śrīmālādevī Siṃhanāda Sūtra (CC BY-SA 4.0)