इषुगमियमां छः

छ् is substituted for the final of 1. इष् 2. गम् and 3. यम् before a Present-character (शित्).
As इच्छति, गच्छति, यच्छति ॥ The इष् with the indicatory उ is taken here, (Tudadi 50), and not इष् of Divadi (19) class or of Kryadi class (53). There we have इष्यति and इष्णाति respectively. Those who do not read the sutra as इषु &c, but as इषगमि &c, read the anuvritti of the word अचि from 7.3.72 into this sutra; so that the शित् is qualified by the word अच्, i.e. a शित् affix which is merely a vowel, and has no consonant in it; (and not a शित् affix which begins with a vowel). Therefore though शानच् is a शित् affix beginning with a vowel, yet as it contains a consonant, the छ substitution does not take place, as इषाणः 3.1.83 The reading of the text according to Patanjali and Katyayana is इषगमियमां छ, and hence the necessity of the above explanation. The reading इषु, though convenient, is not arsha.