What does “the meaning is complete without it” signify in īghāl?

Iṭnāb: Clarification after Ambiguity, Tawshīʿ, Repetition and Īghāl

• The preceding passage is meaningless without the ending
• The final word only satisfies meter
• The ending is dispensable for the core proposition but still useful
• The final wording negates the earlier proposition