هَلَّا انْتَهَجْتَ ... فَمَا إِعْدَادُكَ ... فَمَنْ نَصِيرُكَ؟
Why have you not taken the road ... what is your preparation ... who is your helper?
Hallā urges action while reproaching its absence. Mā asks about the nature of preparation or excuse, and man asks about a person or personal helper. They do not have identical grammatical functions.
The questions change form while retaining one rhetorical purpose: expose inaction and misplaced confidence.