As the arrival date of the divine mother draws near, the silt from the holy Ganga River is collected. Lots of people from all over Bengal come to the shore of Ganga and picks up the wet sand or clay after offering their prayers. This clay is then taken to Kumortuli, where it is used to mould the shape of Goddess Durga and her family who comes along with her.

The clay is called 'Ganga Mati', and is considered sacred. It is beleived that the shape of Devi Durga can only be moulded by the holy sand of Ganga.

“Some men must follow, and some command, though all are made of clay.”