Which statement correctly explains the aspect “Hallā and alā” in the example “هَلَّا / أَلَا”?

Inshāʾ and Tamannī: Requests, Wishing, Exhortation, and Reproach

• Context and the rhetorical choice of request — Wishing, questioning as a wish, conditional wishing, and exhortation.
• Hallā and alā — Why not? / Come, do it.
• Examples of non-requesting inshāʾ — How excellent a man Zayd is!
• Interrogative hal used as a wish — Would that I had an intercessor.