The na of ayana is changed to ṇa , when preceded by the word antar and the word does not denote a country.,
Thus अन्तरयणं शोभनम् ॥ Why do we say
ot denoting a country\? Observe अन्तरयनो देशः ॥ This ण change would have taken place by 8.4.29, this special sutra is for आदेश purposes. The word अयन is formed by ल्युट् added to अय् or इण् ॥,