Ījāz al-ḥadhf (إيجاز الحذف) omits a constituent whose sense is recoverable from the remaining expression or the known situation. The omission may shorten the statement, shift attention to the main point or involve the listener in recovering the meaning.
Two conditions are essential: the missing sense must be recoverable, and the intended meaning must remain secure. Without suitable evidence, omission can become ambiguity or a defective statement.
Grammatical reconstruction and the rhetorical reason for omission are related but distinct tasks; good analysis identifies both.