At this point, Krishna considers a hypothetical possibility to cover all grounds and checkmate Arjuna. If, however, (atha) Arjuna (tvaṁ) thinks (manyase) that the soul (cainaṁ) always takes birth (nitya-jātaṁ) or (vā) always dies (nityaṁ mṛtam), even then (tathāpi), he still has no (na) reason to (arhasi) lament (śocitum) it (enaṁ). (BG 2.26) From various angles, Krishna establishes the point that Arjuna has no reason to lament in any case.

Indeed (hi), for one who has taken birth (jātasya), death (mṛtyur) is certain (dhruvo), and (ca) for one who has died (mṛtasya), birth (janma) is certain (dhruvaṁ). Therefore (tasmād), in an unavoidable (aparihārye) matter (arthe), Arjuna (tvaṁ) has no reason to lament (na śocitum arhasi). (BG 2.27) After stating this inevitable fact, Krishna brings out a general principle. All beings (bhūtāni) are unmanifest (avyakta) in the beginning (ādīni), manifest (vyakta) in the interim stage (madhyāni), and certainly (eva) unmanifest (avyakta) in the end (nidhanāny); what (kā) is there (tatra) to lament for (paridevanā)? (BG 2.28)

Indeed, the soul is a source of amazement for everyone. Someone (kaścid) sees (paśyati) the soul (enam) as amazing (āścarya-vat), and (cā) another (anyaḥ) describes it (vadati) as amazing (āścarya-vad), and (ca) another (anyaḥ) hears (śṛṇoti) of it (enam) as amazing (āścarya-vac). And (caiva), someone (kaścit), even after hearing (śrutvāpy), cannot (na) understand (veda) it (enaṁ). (BG 2.29)

Krishna finally comes to His original point and concludes this section. This (ayaṁ) embodied soul (dehī) dwelling in every (sarvasya) body (dehe) is always (nityam) deathless (avadhyo). Therefore (tasmāt), Arjuna (tvaṁ) has no (na) reason (arhasi) to lament (śocitum) for any being (sarvāṇi bhūtāni). (BG 2.30)