Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 39
Sanskrit:
यत्सेवयाशेषगुहाशय: स्वराड्विप्रप्रियस्तुष्यति काममीश्वर: ।तदेव तद्धर्मपरैर्विनीतै:सर्वात्मना ब्रह्मकुलं निषेव्यताम् ॥ ३९ ॥
ITRANS:
yat-sevayāśeṣa-guhāśayaḥ sva-rāḍvipra-priyas tuṣyati kāmam īśvaraḥtad eva tad-dharma-parair vinītaiḥsarvātmanā brahma-kulaṁ niṣevyatām
Translation:
The Supreme Personality of Godhead, who is everlastingly independent and who exists in everyone’s heart, is very pleased with those who follow in His footsteps and engage without reservation in the service of the descendants of brāhmaṇas and Vaiṣṇavas, for He is always dear to brāhmaṇas and Vaiṣṇavas and they are always dear to Him.
Purport:
It is said that the Lord is most pleased when He sees one engage in the service of His devotee. He does not need any service from anyone because He is complete, but it is in our own interest to offer all kinds of services to the Supreme Personality of Godhead. These services can be offered to the Supreme Person not directly but through the service of brāhmaṇas and Vaiṣṇavas. Śrīla Narottama dāsa Ṭhākura sings, chāḍiyā vaiṣṇava-sevā nistāra pāyeche kebā, which means that unless one serves the Vaiṣṇavas and brāhmaṇas, one cannot get liberation from the material clutches. Śrīla Viśvanātha Cakravartī Ṭhākura also says, yasya prasādād bhagavat-prasādaḥ: by satisfying the senses of the spiritual master, one can satisfy the senses of the Supreme Personality of Godhead. Thus this behavior is not only mentioned in scriptures but also followed by ācāryas. Pṛthu Mahārāja advised his citizens to follow the exemplary behavior of the Lord Himself and thus engage in the service of brāhmaṇas and Vaiṣṇavas.