The term "Shaivite" is overused nowadays. For instance, Iyer Brahmins are often called Shaivites, but they're actually followers of Adi Shankaracharya's Smartha sect (which I discuss here and here), and simply adopt Shiva as their Ishta Devata. True philosophical Shaivism is relatively rare nowadays (in contrast to philosophical Vaishnavism which is pretty common). I discussed one genuine Shaivite sect, the Lingayat sect of Basava, in my answer here. But my question is related to a more famous sect of Shaivism, known as Shaiva Siddhanta.
Just as the Sri Vaishnava sect (of which I am a member) is based on the Pancharatra Agamas and the poems of the 12 Alwars, Shaiva Siddhanta is based on the Shaiva Agamas and the poems of the 63 Nayanars. In any case, one of the defining works of the Shaiva Siddhanta sect is Meykandar's Shivajnana Bodham, a commentary on twelve important verses of a Shaiva Agama called the Raurava Agamas. Now Meykandar's shishya Arrulnandi Shivacharya wrote a commentary on the Shivajnana Bodham called the Shivajnana Siddhiyar. Here is the invocatory verse to Ganesha that the Shivajnana Soddhiyar starts with:
O God Ganesha, with the elephant head, single-tusked, double-eared, triple-juiced, with the hanging lip, and five hands, begotten by the Lord with the braided hair, adorned with the Ganges, the crescent moon and the cassia flowers, Thy feet will remove without fail the evil in our hearts flowing with love, humility, and knowledge, night and day. Thy feet will lift such far above the delights of Brahma and Vishnu.
Now most of these attributes of Ganesha are recognizable: having an elephant head, having one tusk (as I discuss here), being the son of Shiva, being the remover of obstacles, etc. But my question is, what scriptures describe Ganesha having five hands?
The translator claims that these represent the five functions that Shaivites believe Sadashiva performs: creation, preservation, destruction, obscuraton, and liberation. But I'm generally skeptical of such symbolic explanations. In any case, where exactly is Ganesha's fifth hand? Is his trunk being counted as an extra hand?