لَيْتَ لِي أَلْفَ دِينَارٍ
If only I had a thousand dinars.
The textbook presents this as the words of a financially distressed person. Obtaining money is not intrinsically impossible, but receiving so large an amount is unlikely in that person's circumstances. It is therefore an example of tamannī.
lī is a prepositional phrase functioning as a fronted predicate of layta; alfa is its delayed accusative noun, and dīnārin is the genitive complement. The rhetorical classification depends on context, not merely the sum named.