Bhashya
विदितवन्त इत्यर्थः ।यथा च वयं ब्रह्म विदित्वा अस्माद्वि-नशनाद्विप्रमुक्ताः, एवं ये तद्विदुः अमृतास्ते भवन्ति; येपुनः नैवं ब्रह्म विदुः, ते इतरे ब्रह्मविद्भ्योऽन्ये अब्रह्मविदइत्यर्थः, दुःखमेव जन्ममरणादिलक्षणमेव अपियन्ति प्रति-पद्यन्ते, न कदाचिदपि अविदुषां ततो विनिवृत्तिरित्यर्थः;दुःखमेव हि ते आत्मत्वेनोपगच्छन्ति ॥
In plain words
'They have come to know' — that is the meaning. Just as we, once we have known Brahman, are freed from this dying, so too anyone who knows That becomes immortal. But those who do not know Brahman this way are simply other — different from the knowers of Brahman, meaning, they are those who do not know Brahman. They fall straight into suffering, the kind marked by birth, death, and all the rest, and for the ignorant that suffering never lets up, not even once — that is the meaning. Because they have taken suffering itself and mistaken it for their own self.
Close to the Sanskrit
'They have known' — that is the meaning. And just as we, having known Brahman, are freed from this perishing, so those who know That become immortal; those who, on the other hand, do not know Brahman thus, are other, different from the knowers of Brahman, that is, non-knowers of Brahman — that is the meaning — fall only into suffering characterized by birth, death, and so on; never at any time is there any cessation of that for the ignorant — that is the meaning; for they take on suffering itself as their very self.