Quotes from The Saṃyukta Āgama, Vol. 14
“One must understand the origin of the Dharma to be able to comprehend nirvana.”
《雜阿含經》卷 14
「先知法住，後知涅槃」
Remarks:
The intellectual Susima was sent by non-Buddhists to act as an undercover to Gautama Buddha’s sangha group and to plagiarize His teachings (dharma).
Susima asked the monastics in the sangha group, who claimed to know nirvana, if they had all attained various states of samadhi. They all said they had not, and upon hearing their answers, Susima asked the Buddha, “How could these sanghas claim to know nirvana when they have not attained any state of samadhi?”
The Buddha enlightened Susima by stating that one must understand the origin of the dharma before being able to understand nirvana. The Buddha clearly meant that a correct understanding of the true dharma is vital, rather than simply cultivating the samadhi. In other words, to attain liberation, one must rely on wisdom, not meditation.