SB 1.3.8

tṛtīyam ṛṣi-sargaṁ vai
 devarṣitvam upetya saḥ
tantraṁ sātvatam ācaṣṭa
 naiṣkarmyaṁ karmaṇāṁ yataḥ
Synonyms: 
tṛtīyam — the third one; ṛṣi-sargam — the millennium of the ṛṣis; vai — certainly; devarṣitvam — incarnation of the ṛṣi amongst the demigods; upetya — having accepted; saḥ — he; tantram — exposition of the Vedas; sātvatam — which is especially meant for devotional service; ācaṣṭa — collected; naiṣkarmyam — nonfruitive; karmaṇām — of work; yataḥ — from which.
Translation: 
In the millennium of the ṛṣis, the Personality of Godhead accepted the third empowered incarnation in the form of Devarṣi Nārada, who is a great sage among the demigods. He collected expositions of the Vedas which deal with devotional service and which inspire nonfruitive action.
Purport: 

The great Ṛṣi Nārada, who is an empowered incarnation of the Personality of Godhead, propagates devotional service all over the universe. All great devotees of the Lord all over the universe and in different planets and species of life are his disciples. Śrīla Vyāsadeva, the compiler of the Śrīmad-Bhāgavatam, is also one of his disciples. Nārada is the author of Nārada-pañcarātra, which is the exposition of the Vedas particularly for the devotional service of the Lord. This Nārada-pañcarātra trains the karmīs, or the fruitive workers, to achieve liberation from the bondage of fruitive work. The conditioned souls are mostly attracted by fruitive work because they want to enjoy life by the sweat of their own brows. The whole universe is full of fruitive workers in all species of life. The fruitive works include all kinds of economic development plans. But the law of nature provides that every action has its resultant reaction, and the performer of the work is bound up by such reactions, good or bad. The reaction of good work is comparative material prosperity, whereas the reaction of bad work is comparative material distress. But material conditions, either in so-called happiness or in so-called distress, are all meant ultimately for distress only. Foolish materialists have no information of how to obtain eternal happiness in the unconditional state. Śrī Nārada informs these foolish fruitive workers how to realize the reality of happiness. He gives direction to the diseased men of the world how one’s present engagement can lead one to the path of spiritual emancipation. The physician directs the patient to take treated milk in the form of curd for his sufferings from indigestion due to his taking another milk preparation. So the cause of the disease and the remedy of the disease may be the same, but it must be treated by an expert physician like Nārada. The Bhagavad-gītā also gives the same solution of serving the Lord by the fruits of one’s labor. That will lead one to the path of naiṣkarmya, or liberation.