fafataḥnā
So We opened
REM – prefixed resumption particle fa + V – 1st person plural perfect verb + PRON – 1st person plural object pronoun nā
Root Link: ف ت ح
bimāin
with water
P – prefixed preposition bi + N – genitive masculine indefinite noun
Root Link: م و ه
mun'hamirin
pouring down
N – genitive masculine indefinite (form VII) active participle
Root Link: ه م ر