[Worldtraveler once upon a time]

The video is well known to me. Are you missing the last syllable by reading the translation at the bottom of the video? Not "masih," but "masihka?" Three syllables, rather than two?

Reference: https://www.youtube.com/watch?v=AyrSiZrQ5ko

[lightman]

The final syllable is not pronounced separately and distinctly but is slurred/combined with the beginning of “Qam”.

I know many Arabic Christians and have heard the final syllable in speech, less so in music (but that is the nature of song)