One of Farid's biggest hits. We could argue about whether the song is in Nawa Athar or Nahawand, but Nawa Athar wins because it ends all of the verses and the chorus. But most of the verse modulations belong more to the world of Nahawand than to Nawa Athar. Quite frankly, Nawa Athar is a fairly rare maqam in Arabic music (though much more common in Turkish music and Gypsy musics), so aside from the maqam hybridization already going on in the 1950's, Farid probably felt he needed to bring in some more ajnas to make it more interesting--and somehow he always ends up in Jins Bayati one way or the other!
See the following analyses: Jins Nahawand & Nakriz, Jins Hijazkar, Jins Hijaz, Jins Bayati & Saba, Jins Bayati and Hijaz Baggage