Not entire sure what a 'jubah' is, but this pattern is one that I have seen in a variety of middle eastern clothing. And it looks damn comfy so I will likely end up making at least one of these for myself.
Dress sew tailor Pola princess line
How to measure for an abaya
Cara Menjahit Pakaian: Pola Gamis Dengan Krah Syal
Rumah Jahit Aisha Zahran: Cara Membuat Pola Praktis