What type of hamzatul wasl is there in the word ibni as in surah ghafir:ayah 36

Question
The type of hamzatul wasl in the word eesa ibnu maryam as in surah maryam ayah-34 is—hamzatul wasl in nouns and its irregular noun
But what type of hamzatul wasl is there in the word ibni as in surah ghafir:ayah 36---because according to meaning it’s a noun ..so my question is what type of hamzatul wasl is it—is it hamzatul wasl in verb (present tense verb in three letter word)

Answer
The word  in aayah 36 of surah Ghaafir is a command form of a three letter make up of a verb : To build .  So in it Firawn (Pharaoh),  is commanding that a tower be built.   The third letter of the command form has a kasrah, so we begin this hamzah al-wasl with a kasrah. 
This is different from the other word with the same spelling which means son and is a noun. 
Hamzah Al-wasl does not enter present tense verbs. 
The following table explains which type of regular verbs the  can enter: