He is irresistibly drawn by the practice he had pursued earlier. Even an enquirer of the science of yoga rises above the ken of Vedic rituals and their promises.
How assuring is Krishna’s pronouncement! Arjuna is doubtful and fearful about the fate of not being able to complete his yogic pursuit. Whether true or not, the fear has to be dispensed with. The only way is to assure Arjuna as Krishna dexterously does.
The incumbent will irresistibly commence the practice from where he had left it. With enhanced vigour and resolve, the yoga-bhraṣṭa (one fallen from yoga pursuit) takes up the practice and fulfils it gloriously.
Krishna also evaluates the yogic pursuit. Even one wishing to know what yoga is, not to speak of the practitioner, gains sufficient religious and spiritual merit, that he rises above the Vedic ken.
Vedas are too sacred, and their rituals and ceremonies are sacrosanct. Even then, one wanting to know what yoga is, transcends all of them. He gets far more than what Vedas can bestow. What an amazing revelation!