This verse is from the Bhagavad Gita, Chapter 6, Verse 41. It is written in Sanskrit and translates to English as follows:
prāpya puṇya-kṛitāṁ lokān uṣhitvā śhāśhvatīḥ samāḥ
śhuchīnāṁ śhrīmatāṁ gehe yoga-bhraṣhṭo ’bhijāyate || 41 ||
"Or else that sadhak takes birth in a family of wise and spiritual yogis. Such a birth is extremely rare and valuable in this world."
Explanation in detail:
Lord Krishna is trying to explain in this verse that no spiritual effort goes to waste. Even a person who is unsuccessful in yoga can continue his sadhana by taking birth in more advanced circumstances in the next birth. Such a birth is extremely rare as it helps one to directly move to the path of salvation.
ātva – or else
yoginām – yogis (spiritual sadhaks)
eva – hi
kulē – family, family
bhavati – is born, is born
dhimatām – intelligent, prudent
etat – this
hi – certainly
durlabhataram – very rare, very difficult to get
loke – in the world
janma – birth
yad idrsham – such, of this kind