醝字門，入諸法醝字不可得故
"The letter YSa is a gateway because the ‘YSa-character’ of all dharmas cannot be apprehended."
Kumarajiva
入逸娑字門，悟一切法衰老性相不可得故
"Enter the gateway of the letter YSa, because one realizes that the nature and characteristics of decay (ysara=jarā) in all dharmas cannot be apprehended."
Xuanzang
YSA because no decay (ysara=jarā) is apprehended
Conze
The syllable YSa [means] all mental phenomena are of the non-recognition of
aging.
Jayarava