राजविद्या राजगुह्यं पवित्रमिदमुत्तमम्।प्रत्यक्षावगमं धर्म्यं सुसुखं कर्तुमव्ययम्॥
rāja-vidyā rāja-guhyaṃ pavitram idam uttamampratyakṣāvagamaṃ dharmyaṃ su-sukhaṃ kartum avyayam
Word by word
The verse says
This is the king of knowledge, the king of secrets, the purest, the highest. It can be seen directly. It agrees with what is right, it is very easy to practise, and it does not wear out.
In plain words
Five claims in one line, and the strange one is in the middle.
Pratyakṣa — directly seen. Check it yourself. That is an unusual thing for scripture to offer.
And then su-sukhaṃ kartum — very easy to do. Not hard. Easy.
Where you've felt this · in health
Your doctor tells you that twenty minutes of walking a day will make you feel better. It sounds far too simple to bother with, and you nearly do not. Two weeks in you notice you are sleeping better. Nobody had to argue you into believing it, and no argument would have worked as well.
Going deeper
Inviting people to check is not the usual posture of a sacred text, and the invitation is genuine.
Pratyakṣa means what is in front of the eyes — the word used in Indian philosophy for direct perception, the most trusted way of knowing anything. Krishna applies it to this teaching. Do it and see. The claim is not that you should take his word for it; it is that his word can be tested by the person who was asked to take it.
Easy to practise is the other surprise, sitting where you would expect a warning about how difficult the path is.
What both claims do is shift the burden. If this is checkable and not hard, then the reason most people do not find out is not that the gate is guarded. It is that nobody got round to trying the handle.