Bhashya
किंदेवतोऽस्यामुदीच्यां दिश्यसीति, सोमदेवत इति--सोम इति लतां सोमं देवतां चैकीकृत्य निर्देशः ।स सोमःकस्मिन्प्रतिष्ठित इति, दीक्षायामिति-- दीक्षितो हि यज-मानः सोमं क्रीणाति ; क्रीतेन सोमेन इष्ट्वा ज्ञानवानुत्तरांदिशं प्रतिपद्यते सोमदेवताधिष्ठितां सौम्याम् ।कस्मिन्नुदीक्षा प्रतिष्ठितेति, सत्य इति-- कथम्? यस्मात्सत्येदीक्षा पतिष्ठिता, तस्मादपि दीक्षितमाहुः-- सत्यं वदेति--कारणभ्रेषे कार्यभ्रेषो मा भूदिति ।सत्ये ह्येव दीक्षा प्रति-ष्ठितेति ।कस्मिन्नु सत्यं प्रतिष्ठितमिति ; हृदय इति होवा-च ; हृदयेन हि सत्यं जानाति ; तस्मात् हृदये ह्येव सत्यंप्रतिष्ठितं भवतीति ।एवमेवैतद्याज्ञवल्क्य ॥
In plain words
What god watches over you in the north? Soma, he says — one word doing double duty for the creeper and the god at once. What holds Soma up? Initiation — because it's the initiated sacrificer who buys the Soma in the first place, offers it, and by that very act reaches the northern quarter that Soma itself presides over. What holds initiation up? Truth. Why? Because if the cause slips, the effect slips with it — so an initiated person is told: speak the truth, so that never happens. And what holds truth up? The heart, he says, because the heart is what knows truth in the first place. That's where truth finally comes to rest. Just so, Yajnavalkya, just so.
Close to the Sanskrit
'What deity do you have in this northern direction?' — 'Soma is my deity', he said — 'Soma' [here] is a designation formed by treating the creeper and the deity Soma as one. 'On what is that Soma founded?' — 'On initiation', he said — for the initiated sacrificer buys Soma; having sacrificed with the purchased Soma, the man of knowledge attains the northern direction, the one presided over by the deity Soma. 'On what, then, is initiation founded?' — 'On truth' — how so? Since initiation is founded on truth, they also say to an initiated person: 'speak the truth' — so that a lapse of the cause not become a lapse of the effect. It is on truth indeed that initiation is founded. 'On what, then, is truth founded?' — 'On the heart', he said; for it is by the heart that one knows truth; therefore it is in the heart indeed that truth comes to be founded. 'Just so it is, Yājñavalkya.'