Shiva Purana
प्रागुदक्प्रवरां किंचित्स्थापयेन्मूलविद्यया ॥ पिंडिकां चाथ संयोज्य शाक्तं मूलमनुस्मरन् ॥ ३४ ॥
With the knowledge of the roots one should place something in the east and north. Then he joined the dough and remembered the Shakta root.
english translation
prAgudakpravarAM kiMcitsthApayenmUlavidyayA ॥ piMDikAM cAtha saMyojya zAktaM mUlamanusmaran ॥ 34 ॥
hk transliteration by Sanscript