मनः

The affix ङीप् is not used after a प्रातिपदिक (Nominal Stem) ending in the syllable मन्।
By 4.1.5, pratipadikas ending in मन् would have taken the affix ङीप्, in as much as they end in न्; but the present sutra prohibits that. Thus दामन् 'a string' is both neuter and feminine; and is declined as follows:- I.S. दामा; d. दामानौ, pl. दामानः ॥ Similarly पामा, पामानौ, पामानः ॥

Here by using the term मन् we mean words formed by an affix whose effective element is मन्, such as the affix मनिन् (Unadi IV. 144) in the words दामन् (दो + मानिन्) and पामन्; as well as words which end in मन् which does not represent an affix. This is done on the strength of the following paribhasha :- अनिनसमन ग्रहणान्यर्थवता चनर्थकेन च तदन्तविधिं प्रयोजयन्ति ॥ "Wherever अन् or इन् or अस् or मन्, when they are employed in grammar denote by 1.1.72 something that ends with अन् or इन् or अस् or मन्, there अन्, इन्, अस्, and मन represent these combinations of letters both in so far as they possess, and also in so far as they are void of, a meaning." Therefore, words like सीमन् and अतिमहिमन्, where मन् is not an affix, but an integral part of the word, are also governed by the present sutra. Thus, सीमा, सीमानौ, सीमानः अतिमहिमा, अतिमाहमानौ and अतिमहिमानः ।