Bg 7.17

tesam jnani nitya-yukta
eka-bhaktir visisyate
priyo hi jnanino ’tyartham
aham sa ca mama priyah

Word for word: 
tesam — out of them; jnani — one in full knowledge; nitya-yuktah — always engaged; eka — only; bhaktih — in devotional service; visisyate — is special; priyah — very dear; hi — certainly; jnaninah — to the person in knowledge; atyartham — highly; aham — I am; sah — he; ca — also; mama — to Me; priyah — dear.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Of these, the one who is in full knowledge and who is always engaged in pure devotional service is the best. For I am very dear to him, and he is dear to Me.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Free from all contaminations of material desires, the distressed, the inquisitive, the penniless and the seeker after supreme knowledge can all become pure devotees. But out of them, he who is in knowledge of the Absolute Truth and free from all material desires becomes a really pure devotee of the Lord. And of the four orders, the devotee who is in full knowledge and is at the same time engaged in devotional service is, the Lord says, the best. By searching after knowledge one realizes that his self is different from his material body, and when further advanced he comes to the knowledge of impersonal Brahman and Paramatma. When one is fully purified, he realizes that his constitutional position is to be the eternal servant of God. So by association with pure devotees the inquisitive, the distressed, the seeker after material amelioration and the man in knowledge all become themselves pure. But in the preparatory stage, the man who is in full knowledge of the Supreme Lord and is at the same time executing devotional service is very dear to the Lord. He who is situated in pure knowledge of the transcendence of the Supreme Personality of God is so protected in devotional service that material contamination cannot touch him.