कार्याख्यानादपूर्वम् ॥ १८ ॥
kāryākhyānādapūrvam || 18 ||
kāryākhyānāt—On account, of being a restatement of an act (already enjoined by the Smriti); apūrvam—what has not been so enjoined elsewhere.
18. On account of (the rinsing of the mouth with water referred to in the Prana Vidya) being a restatement of an act (already enjoined by the Smriti), what has not been so enjoined elsewhere (is here enjoined by the Sruti).
In the Chhandogya 5. 2. 2. and the Brihadaranyaka 6. 1. 14 we find a reference to the rinsing of the mouth with water before and after a meal, thinking that thereby Prana is dressed. The question is whether the Sruti enjoins both or only the latter. The Sutra states that since the former, the act of rinsing, is already enjoined on everyone by the Smriti, the latter act of thinking the water as the dress of Prana is alone enjoined by the Sruti.