The na of āni , the affix of the Imperative, First Person, is changed into ṇa when it follows a letter competent to cause such a change standing in an upasarga,
The word आनि is the termination of the Imperative. Thus प्रवपाणि, परिवपाणि, प्रयाणि, परियाणि ॥
Why do we say 'the Imperative'? Observe प्रवपानि मासानि ॥ Here आनि is the neuter plural termination, and the word means प्रकृष्टा वपा येषु, तानि ॥
According to Padamanjari, the employment of the word लोट् in the sutra is redundant. For without it also आनि would have meant the Imperative affix, and not the Neuter termination, on the maxim of अर्थवद् ग्रहणे &c. Moreover in the noun प्रवपानि, प्र is not an upasarga at all, on the maxim यत् क्रियायुक्ताः प्रादयस्तं प्रति गति-उपसर्ग-संज्ञे भवतः ॥,