(Fayakun). 'Allah says the Word of Command "Be!" ("Kun!") to the non-existent immutable entities and they instantaneously 'become' and gain existence. "Be and it becomes", ("Kun fayakun").
(Kana Maktub). This phrase indicates that fate or destiny has been written by the Pen upon the Preserved Tablet, and the ink is dry. There is no changing it.