The affix kha comes after the words 1. aṣaḍakṣa 2. āśitaṅgu 3. alaṃkarma 4. alampuruṣa and after a stem ending in adhi,
The force of ख is स्वार्थ i e. it does not change the sense of the word. The word अषडक्ष means \that which has not six eyes\. षडक्ष is compounded from षट् + अक्ष्णि by adding षच् 5.4.113 \having six eyes\. The affix ख is to be added to this word already ending in the affix shach. Thus अषडक्षीणे मन्त्रः \a secret not having six eyes\. i. e. \a secret known or determined by two persons only to the exclusion of a third\. Similarly आशितंगवीनं अरण्यम् = आशिता गावोऽस्मिन्नरण्ये = प्रभूतयवसं \a forest where formerly cattle had grazed\. The augment मुम् is added to आशित by nipata, or irregularly. So also अलंकर्मीणः = अलं समर्थः कर्मणे पर्याप्तः = competent to do any act, clever. So अलं पुरुषीणः = अलं समर्थः पुरुषाय = प्रतिमल्लादिः = fit for a man.
A word ending with अधि, will be a Tatpurusha compound, by (II. I. 40), as the word अधि belongs to Saundadi class. As राजाधीनः ॥
The affix kha in the case of these words is invariable (nitya), because the word विभाषा occurs in the next sutra; and it is a maxim of interpretation that a rule occurring between two optional rules is nitya. The above words always occur with this affix and never without it. while in the case of other words taught hereafter this affix comes optionally. There are other affixes also which are svarthika and nitya. Such as तमप् &c up to the affix कन् 5.3.55 to 5.3.95 भ्य &c upto वुन् 5.3.112 to 5.4.1 आम् &c upto मयट्, 5.4.11 to 5.4.21 and affixes taught from 5.4.6 i.e. कन् to 5.4.9. (ख). ending in जाति and all Samasanta affixes.,
