This verse is from the Bhagavad Gita, Chapter 6, Verse 43. It is written in Sanskrit and translates to English as follows:
tatra taṁ buddhi-sanyogaṁ labhate paurva-dehikam
yatate cha tato bhūyaḥ sansiddhau kuru-nandana || 43 ||
"In that state, the person gains the wisdom produced by the spiritual impressions of his previous life and again strives to attain siddhi (salvation), O Arjuna, descendant of the Kuru dynasty."
Explanation in detail:
This shloka indicates that the person who came close to perfection through yoga and spiritual effort in his previous life naturally attains spiritual knowledge and inclination as a result of those efforts in the next life. Such a person finds it easy to advance on the path of his self-development, and he continuously strives towards perfection.
Tatra - there, in that situation (due to the influence of the sanskaras of the previous life).
Tam - him, that person.
Buddhi-Samyogam - association of spiritual wisdom and knowledge.
Labhate - acquires.
Paurvadehikam - of the previous life, pertaining to the purva deha (body).
Yatate - strives.
Cha - and.
Tatah - then, after that.
Bhuyah - more, more.
Samsiddhau - perfection, siddhi or siddhi.
Kuru-Nandana - Giver of happiness (address to Arjuna) of the Kuru dynasty.