妙法蓮華經玄贊 10.193

10.193

解妨者，問：菩薩願力神功皆等，何故唯此獨名藥王？答：論功據行、果實無差，願利、修因昔亦微別。只如救生拔苦行願菩薩皆同，觀音獨得救名，藥王何妨偏勝。

As for resolving difficulties: Question: The vow-power and divine efficacy of bodhisattvas are all equal; why is this one alone uniquely named Medicine King (Bhaiṣajyarāja)? Answer: Speaking of merit based on practice, the fruits are truly without difference; yet regarding the vows that benefit and the causes cultivated in the past, there are also slight distinctions. Just as bodhisattvas are all identical in their practices and vows to rescue sentient beings and alleviate suffering, yet Avalokiteśvara alone obtains the name of rescuer, what is there to prevent Bhaiṣajyarāja from being uniquely preeminent [in healing]?