President Mrs. Pratibha Devi Singh Patil and Vice President Mr. Hamid Ansari have greeted the nation on the occasion Milad-Un-Nabi, the birthday of the Holy Prophet Mohammed being observed tomorrow.In her greetings, Mrs Patil expressed hope that Holy Prophet's message of universal brotherhood, compassion, tolerance and service to humanity will guide and inspire the people to follow the path of harmony. In his message Mohammed Ansari said that Prophet's teachings of love, humanism, righteousness and tolerance continue to be a source of spiritual strength for all humanity.