大般涅槃經義記 3.129

3.129

自下第四喻明遣邪。「爾時童子經理是」已牒前生後，經理癈邪立正事已，「復以解藥與栴陀」者，懺罪之法名為解藥，授之令懺名與栴陀，除罪心喜說為「醒悟」，彼犯重罪，雖復懺竟猶須擯遣，令遠清眾，名「驅出竟」。

From here down is the fourth metaphor, explaining the dispatching of the heterodox. 'At that time, the young man, having arranged this...' reviews what came before to introduce what follows; having arranged the matter of deposing the heterodox and establishing the correct, 'further gave the antidote to the caṇḍāla' means that the method for repenting transgressions is called the antidote; conferring it to make him repent is called giving it to the caṇḍāla; eliminating transgressions so that the mind rejoices is spoken of as 'sobering and awakening.' Because he committed grave offenses, although he has repented, he must still be expelled to keep him far from the pure assembly, which is called 'completely driven out.'