SB 4.28.32

agastyaḥ prāg duhitaram
 upayeme dhṛta-vratām
yasyāṁ dṛḍhacyuto jāta
 idhmavāhātmajo muniḥ
Synonyms: 
agastyaḥ — the great sage Agastya; prāk — first; duhitaram — daughter; upayeme — married; dhṛta-vratām — taken to vows; yasyām — through whom; dṛḍhacyutaḥ — named Dṛḍhacyuta; jātaḥ — was born; idhmavāha — named Idhmavāha; ātma-jaḥ — son; muniḥ — the great sage.
Translation: 
The great sage named Agastya married the first-born daughter of Malayadhvaja, the avowed devotee of Lord Kṛṣṇa. From her one son was born, whose name was Dṛḍhacyuta, and from him another son was born, whose name was Idhmavāha.
Purport: 

The name Agastya Muni is very significant. Agastya Muni represents the mind. The word agastya indicates that the senses do not act independently, and the word muni means “mind.” The mind is the center of all the senses, and thus the senses cannot work independent of the mind. When the mind takes to the cult of bhakti, it engages in devotional service. The cult of bhakti (bhakti-latā) is the first daughter of Malayadhvaja, and as previously described, her eyes are always upon Kṛṣṇa (asitekṣaṇām). One cannot render bhakti to any demigod. Bhakti can be rendered only to Viṣṇu (śravaṇaṁ kīrtanaṁ viṣṇoḥ). Thinking the Absolute Truth to be without form, the Māyāvādīs say that the word bhakti can apply to any form of worship. If this were the case, a devotee could imagine any demigod or any godly form and worship it. This, however, is not the real fact. The real fact is that bhakti can be applied only to Lord Viṣṇu and His expansions. Therefore bhakti-latā is dṛḍha-vrata, the great vow, for when the mind is completely engaged in devotional service, the mind does not fall down. If one tries to advance by other means — by karma-yoga or jñāna-yoga — one will fall down, but if one is fixed in bhakti, he never falls down.

Thus from bhakti-latā the son Dṛḍhacyuta is born, and from Dṛḍhacyuta the next son, Idhmavāha, is born. The word idhma-vāha refers to one who carries wood for burning in a sacrifice when approaching a spiritual master. The point is that bhakti-latā, the cult of devotion, fixes one in his spiritual position. One so fixed never comes down, and he begets children who are strict followers of the śāstric injunctions. As said in the Vedas:

tad-vijñānārthaṁ sa gurum evābhigacchet
 samit-pāṇiḥ śrotriyaṁ brahma-niṣṭham

In the line of devotional service, those who are initiated are strict followers of the Vedic scriptural injunctions.