The Hebrew particle epho (H645) is an interrogative or emphatic particle meaning "then," "now," "so," or "I pray." It is often used in rhetorical questions to press a point, or in an exclamatory sense to introduce an emphatic statement. The word adds urgency or emphasis to a question.
As an emphatic particle, epho often appears in moments of crisis or seeking — when a speaker is pressing for an answer, demanding clarity, or crying out in desperation. Job uses similar language in his anguished questioning of God. The word models the kind of honest, direct speech God welcomes from His people, even in suffering.