Shiva Sankalpa (also known as Shiva Sankalpa Suktam) is the 13th section of the Mahanyasam, a comprehensive purification ritual performed before the Sri Rudram abhishekam.
It is a prayer for mental resolve and purification. Each verse ends with the refrain "Tanme manah shiva-sankalpam-astu," meaning "May my mind be filled with auspicious (Shiva) thoughts".