राजविद्या राजगुह्यं पवित्रमिदमुत्तमम्।
प्रत्यक्षावगमं धर्म्यं सुसुखं कर्तुमव्ययम्।।9.2।।
9.2. This shines among the sciences; (this is) the secret of monarchs; it is a supreme purifier, it is comprehensible by immediate perception, is righteous, easy to do, and imperishable.
9.2 Raja-etc. Shines : that which illumines in the midst of all sciences. Here [in the Gita] itself it is said The science of the Self [is the chief] among the sciences. Here in this science kings like Janaka etc., have a right and pervilege (adhikara) [to learn]. It is their secret, as it is much protected (by them) by heroism easy for the Ksatriyas. As they do not waver [in their mind] because of their heroic nature that is common in the members of the warring class, it is very easy to do i.e., to observe. Imperishable : Unlike other actions this action of worshipping Brahman does not perish through the enjoyment of [its result].
Raajavidyaa raajaguhyam pavitramidamuttamam; Pratyakshaavagamam dharmyam susukham kartumavyayam.
rāja-vidyā—the king of sciences; rāja-guhyam—the most profound secret; pavitram—pure; idam—this; uttamam—highest; pratyakṣha—directly perceptible; avagamam—directly realizable; dharmyam—virtuous; su-sukham—easy; kartum—to practice; avyayam—everlasting