Daily Reading: Bhagvad Gita As it is- Page-98

Bg 2.68

tasmād yasya mahā-bāho
nigṛhītāni sarvaśaḥ
indriyāṇīndriyārthebhyas
tasya prajñā pratiṣṭhitā

Translation: 

Therefore, O mighty-armed, one whose senses are restrained from their objects is certainly of steady intelligence.

Purport: 

One can curb the forces of sense gratification only by means of Kṛṣṇa consciousness, or engaging all the senses in the transcendental loving service of the Lord. As enemies are curbed by superior force, the senses can similarly be curbed, not by any human endeavor, but only by keeping them engaged in the service of the Lord. One who has understood this – that only by Kṛṣṇa consciousness is one really established in intelligence and that one should practice this art under the guidance of a bona fide spiritual master – is called a sādhaka, or a suitable candidate for liberation.

Bg 2.69

yā niśā sarva-bhūtānāṁ
tasyāṁ jāgarti saṁyamī
yasyāṁ jāgrati bhūtāni
sā niśā paśyato muneḥ

Translation: 

What is night for all beings is the time of awakening for the self-controlled; and the time of awakening for all beings is night for the introspective sage.

Purport: 

There are two classes of intelligent men. One is intelligent in material activities for sense gratification, and the other is introspective and awake to the cultivation of self-realization. Activities of the introspective sage, or thoughtful man, are night for persons materially absorbed. Materialistic persons remain asleep in such a night due to their ignorance of self-realization. The introspective sage remains alert in the “night” of the materialistic men. The sage feels transcendental pleasure in the gradual advancement of spiritual culture, whereas the man in materialistic activities, being asleep to self-realization, dreams of varieties of sense pleasure, feeling sometimes happy and sometimes distressed in his sleeping condition. The introspective man is always indifferent to materialistic happiness and distress. He goes on with his self-realization activities undisturbed by material reactions.