rabbika
your Lord
N – genitive masculine noun + PRON – 2nd person masculine singular object pronoun ka
Root Link: ر ب ب
takūnanna
be
V – 2nd person masculine singular imperfect verb + EMPH – emphatic suffix nūn
Root Link: ك و ن
l-mum'tarīna
the doubters
DET – determiner prefix al + N – genitive masculine plural (form VIII) active participle
Root Link: م ر ى