"Mudi ondri moovulagangalum" is from "Periyazhvar's thirumozhi".

Tamil nadu back then must have been a highly devotional place so much so that bhakti had pervaded even games! Unthi paraththal is a common game kids play even today. Back then, kids used to take turns while swaying and sing in praise of their favorite god. In these verses the girls sing about rama and krishna!