遮字門，入諸法行不可得故
The syllable ŚCA is a gateway, because one realizes that the practice (caryā) of all dharmas cannot be found.
Kumarajiva
入酌字門，悟一切法聚集足跡不可得故
One enters the gateway of the syllable ŚCA, because it is realized that the cultivation of all dharmas cannot be found.
Xuanzang
The syllable ŚCA is a door to all dharmas. because of the non-apprehension of good conduct ścaraṇa)
Conze
The syllable ŚCA [means] all mental phenomena are openings because of the non-recognition of moral behavior.
Jayarava