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SB 3.21.4

tasyāṁ sa vai mahā-yogī
 yuktāyāṁ yoga-lakṣaṇaiḥ
sasarja katidhā vīryaṁ
 tan me śuśrūṣave vada
Synonyms: 
tasyām — in her; saḥ — Kardama Muni; vai — in fact; mahā-yogī — great mystic yogī; yuktāyām — endowed; yoga-lakṣaṇaiḥ — with the eightfold symptoms of yogic perfection; sasarja — propagated; katidhā — how many times; vīryam — offspring; tat — that narration; me — to me; śuśrūṣave — who am eager to hear; vada — tell.
Translation: 
How many offspring did that great yogī beget through the princess, who was endowed with eightfold perfection in the yoga principles? Oh, pray tell me this, for I am eager to hear it.
Purport: 

Here Vidura inquired about Kardama Muni and his wife, Devahūti, and about their children. It is described here that Devahūti was very much advanced in the performance of eightfold yoga. The eight divisions of yoga performance are described as (1) control of the senses, (2) strict following of the rules and regulations, (3) practice of the different sitting postures, (4) control of the breath, (5) withdrawing the senses from sense objects, (6) concentration of the mind, (7) meditation and (8) self-realization. After self-realization there are eight further perfectional stages, which are called yoga-siddhis. The husband and wife, Kardama and Devahūti, were advanced in yoga practice; the husband was a mahā-yogī, great mystic, and the wife was a yoga-lakṣaṇa, or one advanced in yoga. They united and produced children. Formerly, after making their lives perfect, great sages and saintly persons used to beget children, otherwise they strictly observed the rules and regulations of celibacy. Brahmacarya (following the rules and regulations of celibacy) is required for perfection of self-realization and mystic power. There is no recommendation in the Vedic scriptures that one can go on enjoying material sense gratification at one’s whims, as one likes, and at the same time become a great meditator by paying a rascal some money.