As in ghana घन - ‘thick’, mass
伽字門，入諸法厚不可得故
The syllable GHA is a gateway because the heaviness of all dharmas cannot be found.
Kumarajiva
入鍵字門，悟一切法厚平等性不可得故
The syllable GHA is a gateway because of the understanding that the heaviness of all dharmas cannot be found.
Xuanzang
Because things and persons are not apprehended each as one solid mass (ghana)
Conze
The syllable GHA [means] all mental phenomena are openings because of the non-recognition of the killer (ghana).
Jayarava