Which statement correctly explains the aspect “Wishing versus exhortation” in the example “لَيْتَ / هَلَّا”?

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

• The five requesting forms — Wishing, questioning, command, prohibition and calling.
• Tamannī contrasted with tarajjī — Perhaps the absent person will return.
• Wishing versus exhortation — Would that / Why not (do it)?
• Defining taḥḍīḍ — Why do you not strive? Do strive!