Bhashya
लोकी भवति लोकफलेन युज्यत इत्यर्थः ।लोकान्ननिन्देत् , तद्व्रतम् ॥
In plain words
He becomes a possessor of worlds—meaning he is united with the fruit of the worlds. Let him never disparage the worlds—that is the sacred vow.
Close to the Sanskrit
He becomes a possessor of worlds; he is joined with the fruit of the worlds, this is the meaning. One should not disparage the worlds; that is the observance.