Below is the link to a translation of Nagarjuna’s Treatise on the Twelve Gates and Fa-tsang’s (Fazang) Commentary on that text.
The text is a work by the 7th century Chinese Buddhist Fa-tsang (Fazang) of the Hua-yen (Huayan) School. In the text Fa-tsang explains the key ideas in Nagarjuna’s Treatise on the Twelve Gates (Shih er men lun). This provides a look at Fa-tsang’s understanding of a key text of the Chinese Sanlun school (Three Treatise School) and Madhyamaka Buddhism in China.