The answer is: Held out his spear towards Ai

Josh 8:18 - Described as a javelin in some versions

Joshua was a man of action and divine connection, and one of the most intriguing moments in his leadership appears in the conquest of Ai. As he stands with his spear—or javelin—raised towards the city, we see a powerful image of faith driving strategy. This one simple gesture becomes the signal for an army that had positioned itself strategically to execute God’s command in their conquest. It's fascinating how Joshua, much like Moses with his staff during the parting of the Red Sea, uses a handheld object as a conduit of divine authority.

Interestingly, in ancient warfare, the use of a spear as a rallying point wasn’t just functional; it was symbolic. The act of pointing toward Ai wasn't merely a signal—it was a declaration, inviting all who saw it to act in faith.

This event is also reminiscent of Old Testament echoes where divine intervention shapes history. For instance, the Israelites' conquest of Jericho, marked by miraculous events and divine instruction, gave a foretaste of the thrilling and often intense narratives that follow throughout the Scriptures.

Joshua's tense move symbolizes an intertwining of divine strategy with human obedience, reminding us that leadership often relies on a combination of divine guidance and bold action. He illustrates what it means to wait for action but also to take courageous steps when the moment calls. Their victory at Ai, orchestrated with divine precision, showcases a paradigm of faith in action that resonates through the ages.