ANSWER:

There’s nothing wrong in these words, however it’s an innovation to sing this in the masjids and it is not part of the prescribed salutation upon the Prophet salla Allahu Alaihi wa Sallam which we are rewarded for. 

Is it allowed to say maulaya salliwasallim daiman Abadan .,… It is a nasheed in Arabic I guess,this is being sung in all masjids in our area. So I would like to know whether it is allowed for us to sing it or no??? It does mean about praising Allah for the arrival of prophet Muhammed (S.A.W) peace be upon him.