Now it can be tried to understand if there is any explanation for wearing this Pavithram of kusa grass while performing religious rites and ceremonies. In all cases like this, the popular expressions and their meanings as well as the myths that are in reality allegories containing deep and also hidden truths. Where many of them may be pressed into service.
There is a saying Kusagra Buddhi which means keen intelligence. People somehow have connected this grass kusa with mind or intellect. So our statement that Pavithram of kusa grass has a direct application for mental purity stands supported and strengthened. Further, Lord Subrahmanya, the second born of Siva, is represented by a serpent which symbolizes wisdom. Puranas say that he was born in a Saravana or forest of kusa grass. This fact is highly significant and emphasizes that eventually supports this statement.
The Pavithram made for people performing inauspicious rites and ceremonies, as for instance, the funeral rites for the dead, consists of only one blade of the kusa grass. whereas that made for people performing auspicious ceremonies like the marriage ceremonies consists of two blades. The ceremonies neither auspicious nor inauspicious but performed with spiritual significance as for example the Tarpanam i.e. oblations of water and Sesamum offered to the Pitris or manes on new-moon days require the wearing of Pavithram of kusa grass made of three blades. The number of blades has also its significance. One blade signifies the mental force of one, while two blades signify the force of two i.e. the husband and the wife. The three blades were intended to signify the mental force of the preceptor or some one else added to those of the husband and wife.