BhG 6.42

syntax

atha vā (or now) dhī-matām (of the wise) yoginām eva (just of the yogīs) kule (in the family) bhavati (he becomes).
yat īdṛśam (which like this) janma (birth) etat hi (this indeed) loke (in the world) durlabha-taram [asti] (it is very difficult to obtain).

grammar

atha	–	av. – then, now, moreover, certainly, rather;
vā	–	av. – or, and, on the other side, but even if, however;
yoginām	–	yogin 6n.3 m. – of the yogīs, of those engaged (from: √yuj – to yoke, to join, to engage, yoga – yoga, yoking, application, a means, one of the schools of Hindu philosophy);
eva	–	av. – certainly, just, merely;
kule	–	kula 7n.1 n. – in the family
bhavati	–	√bhū (to be) Praes. P 1v.1 – he becomes;
dhīmatām	–	dhīmant 6n.3 m. – of the wise, of the intelligent (from: √dhī – to think, to consider; dhī – thought, intelligence; -mant / -vant – suffix denoting one who possesses);
etat	–	etat sn. 1n.1 n. – this;
hi	–	av. – because, just, indeed, surely;
durlabhataram	–	dur-labha-tara 1n.1 n. – very difficult to obtain (from: dur / dus – prefix: difficult, bad, hard; √labh – to obtain, to gain; lābha – gain, profit; comparative of: durlabha – durlabha-tara, durlabha-tama)
loke	–	loka 7n.1 m. – in the world;
janma	–	janman 1n.1 n. – birth (from: √jan – to be born);
yat	–	yat sn. 1n.1 n. – that which;
īdṛśam	–	īdṛśa 1n.1 n. – of this kind, like this;

textual variants

bhavati → mahati (in a powerful [family]);
dhīmatām → nirmale (in a spotless [family]);
kule bhavati dhīmatām → jāyate dhī śrīmatāṁ kule (indeed he is born in the family of the wealthy);

Śāṃkara

athavā śrīmatāṃ kulāt anyasmin yoginām eva daridrāṇāṃ kule bhavati jāyate dhīmatāṃ buddhimatām | etat hi janma, yat daridrāṇāṃ yogināṃ kule, durlabhataraṃ duḥkha-labhyataraṃ pūrvam apekṣya loke janma yad īdṛśaṃ yathokta-viśeṣaṇe kule

Rāmānuja

paripakvayogaś calitaś cet, yogināṃ dhīmatāṃ yogaṃ kurvatāṃ svayam eva yogopadeśakṣamāṇāṃ mahatāṃ kule bhavati; tad etad ubhayavidhaṃ yogayogyānāṃ yogināṃ ca kule janma loke prākṛtānāṃ durlabhataram / etat tu yogamāhātmyakṛtam

Śrīdhara

alpa-kālābhyasta-yoga-bhraṃśe gatir iyam uktā | cirābhyasta-yoga-bhraṃśe tu pakṣāntaram āha athaveti | yoga-niṣṭhānāṃ dhīmatāṃ jñāninām eva kule jāyate | na tu pūrvoktānām ārūḍha-yogānāṃ kule | etaj janma stauti īdṛśaṃ yaj janma etad dhi loke durlabhataraṃ mokṣa-hetutvāt

Madhusūdana

dvitīyaṃ prati pakṣāntaram āha athaveti | śraddhā-vairāgyādi-kalyāṇa-guṇādhikye tu bhoga-vāsanā-virahāt puṇya-kṛtāṃ lokān aprāpyaiva yoginām eva daridrāṇāṃ brāhmaṇānāṃ na tu śrīmatāṃ rājñāṃ gṛhe yoga-bhraṣṭa-janma tad api durlabham aneka-sukṛta-sādhyatvān mokṣa-paryavasāyitvāc ca | yat tu śucīnāṃ daridrāṇāṃ brāhmaṇānāṃ brahma-vidyāvatāṃ kule janma | etad dhi prasiddhaṃ śukādivat | durlabhataraṃ durlabhād api durlabhaṃ loke yad īdṛśaṃ sarva-pramāda-kāraṇa-śūnyaṃ janmeti dvitīyaḥ stūyate bhoga-vāsanā-śūnyatvena sarva-karma-saṃnyāsārhatvāt

Viśvanātha

alpa-kālābhyasta-yoga-bhraṃśe gatir iyam uktā | cira-kālābhyasta-yoga-bhraṃśe tu pakṣāntaram āha athaveti | yogināṃ nimi-prabhṛtīnām ity arthaḥ

Baladeva

cirārābdhād yogād bhraṣṭasya gatim āha athaveti | yogināṃ yogam abhyasatāṃ dhīmatāṃ yoga-deśikānāṃ kule bhavaty utpadyate | dvividhaṃ janma stauti etad iti | yogārhāṇāṃ yogam abhyasatāṃ ca kule pūrva-yoga-saṃskāra-bala-kṛtam etaj janma prākṛtānām atidurlabham