Skandapurana 2.4.35.97

2.4.35.97

The māhātmya of the Kārttika full moon is embedded in Śiva's slaying of Tripura with a single arrow. The designation of the month of Āśvina is Iṣa. Iṣa—in [the sense of] wish, desire. Prior to engaging in an action or sacrifice, the awakening of desire regarding the action is necessary. Only then will the path of action be straight. Otherwise, just as the path of nature's growth is crooked, so it will be. It appears that the process of Iṣa, of creating desire, of fashioning a single arrow out of all arrows, is not completed in the month of Āśvina. For this reason, there is the injunction to produce a single arrow on the Kārttika full moon. In Kāṭhaka Saṃhitā 25.1 there is a section called Iṣu, where the name of the Upasad offering is Iṣu. This mention is the transmission of the Purāṇic account into Vedic literature.