俱舍論記 13.171

13.171

「自性善者至猶如良藥」者，釋第二句，明自性善。自性即善，名自性善。猶如良藥，藥即良善，故名良藥。問：何故此五偏名自性，餘善等法非自性耶？解云：此五強勝名為自性，餘非強勝不名自性。又解：無貪等三以翻三不善根，慚、愧二種以翻大不善地法。由所翻法是強勝故，能翻五法名自性善；餘善等法非能翻彼，是故不名自性善也。

Regarding "Intrinsic good... like good medicine": this explains the second line, clarifying intrinsic good. That whose intrinsic nature is itself good is called intrinsic good. It is like good medicine: the medicine itself is wholesome, hence it is called good medicine. Question: Why are these five alone called intrinsic, while the remaining good dharmas are not intrinsic? The explanation says: These five are strong and superior, hence called intrinsic; the others are not strong and superior, hence not called intrinsic. Another explanation: The three beginning with non-greed directly oppose the three unwholesome roots; the two, shame and remorse, directly oppose the major unwholesome ground dharmas. Because the dharmas they oppose are strong and superior, the five opposing dharmas are called intrinsically good; since the remaining good dharmas do not directly oppose them, they are not called intrinsically good.