Bhashya
अङ्गी भवति समग्राङ्गो भवतीत्यथ ।नाङ्गेन हस्तपादा-दिना विहूर्च्छति न कुटिलीभवति, पङ्गु कुणी वा इत्यर्थ ।संवत्सर संवत्सरमात्र मज्ज्ञो मांसानि नाश्नीयात् न भक्ष-येत् ।बहुवचन मत्स्योपलक्षणार्थम् ।मज्ज्ञो नाश्नीयात्सर्वदैव नाश्नीयादिति वा, तद्व्रतम् ॥
In plain words
He becomes complete in his limbs—fully formed, that is the sense. He suffers no failure in any limb, whether hand or foot; he is neither bent nor crippled nor lame. For a full year he avoids eating marrow and flesh, touching neither. The plural form implies fish as well. He must abstain from marrow, or rather, avoid it altogether; this is the vow.
Close to the Sanskrit
He becomes possessed of limbs, complete-limbed he becomes, thus is the meaning. He does not falter with any limb such as hand or foot, nor does he become crooked, lame or maimed, such is the meaning. For a year or year-measure he should not eat marrow and flesh, nor consume them. The plural is for the sake of indicating fish. Marrow he should not eat, or he should never eat it at all, that is the vow.