大方廣佛華嚴經入法界品四十二字觀門 1.25

1.25

捨字時，入隨順一切佛教般若波羅蜜門，悟一切法寂靜性不可得故。

When pronouncing the letter ŚA, one enters the perfection of wisdom door of complying with the teachings of all Buddhas, because one realizes that the tranquil nature (śama/śānta) of all dharmas cannot be apprehended.