tatra taṃ buddhisaṃyogaṃ labhate paurvadehikam |yatate ca tato bhūyaḥ saṃsiddhau kurunandana ||
There he regains the connection with the understanding he had in his former body, and from there he strives again, still harder, toward complete perfection, O joy of the Kurus.
Explanation
Krishna is answering Arjuna's worry about a person whose yoga (spiritual discipline) is unfinished at death. Such a person, born into one of the favorable homes just described, recovers the connection with spiritual understanding (buddhi-saṃyoga) built up in the earlier life. With that as a base, he strives again toward complete perfection (saṃsiddhi), which is liberation.