BG 2.46
यावानर्थ उदपाने सर्वतः सम्प्लुतोदके ।
तावान्सर्वेषु वेदेषु ब्राह्मणस्य विजानतः ॥ ४६ ॥
yāvān artha udapāne
sarvataḥ samplutodake
tāvān sarveṣu vedeṣu
brāhmaṇasya vijānataḥ
yāvān — all that; arthaḥ — is meant; udapāne — in a well of water; sarvataḥ — in all respects; sampluta-udake — in a great reservoir of water; tāvān — similarly; sarveṣu — in all; vedeṣu — Vedic literatures; brāhmaṇasya — of the man who knows the Supreme Brahman; vijānataḥ — of one who is in complete knowledge.
All purposes that are served by the small pond can at once be served by the great reservoirs of water. Similarly, all the purposes of the Vedas can be served to one who knows the purpose behind them.
The rituals and sacrifices mentioned in the karma-kāṇḍa division of the Vedic literature are to encourage gradual development of self-realization. And the purpose of self-realization is clearly stated in the Fifteenth Chapter of the Bhagavad-gītā ( 15.15 ): the purpose of studying the Vedas is to know Lord Kṛṣṇa, the primeval cause of everything. So, self-realization means understanding Kṛṣṇa and one's eternal relationship with Him. The relationship of the living entities with Kṛṣṇa is also mentioned in the Fifteenth Chapter of Bhagavad-gītā. The living entities are parts and parcels of Kṛṣṇa; therefore, revival of Kṛṣṇa consciousness by the individual living entity is the highest perfectional stage of Vedic knowledge. This is confirmed in the Śrīmad-Bhāgavatam ( 3.33.7 ) as follows: