इदं वाव तज्ज्येष्ठाय पुत्राय पिता ब्र-ह्म प्रब्रूयात्प्रणाय्याय वान्तेवासिने ॥
In plain words
This very truth should a father impart to his eldest son, or to a devoted resident disciple.
Close to the Sanskrit
This indeed, a father should proclaim that Brahman to the eldest son, or to a devoted resident pupil.