What does bi-l-silāḥi wa-bi-l-dami clarify in verse 39?

Zuhayr ibn Abī Sulmā: Ḥuṣayn ibn Ḍamḍam, Revenge and the Cost of Bloodshed (Verses 33–42)

• The pleasure of a flood
• The caravan destination
• Mountain height
• A bloody battlefield within the water metaphor