In plain words
The poet, of Kaṇṭam: Our Puruṣōttama has deep compassion for those who hold fast to the three-lettered word [Om], which, by the three-lettered [nirukta, the science of meanings], he made into its three letters [a, u and m]; he unfolded it into three words [the eight-syllabled mantra], brought forth in those three the soul's three marks [being his alone, refuge in him alone, joy for him alone], and in the three became three forms [its master, its refuge and its goal]: his dwelling is the eminent city called Kaṇṭam, on the bank of the Gaṅgā, ringed by great fragrant groves.