During a military campaign, soldiers find themselves far from the holy Temple, unable to physically stand within its courts to pray. Yet, their presence on the battlefield is never a result of their own independent desires. Before embarking on any military action, the nation seeks out God, asking for His guidance and waiting for His direction [מצודת דוד]. Only after receiving His command do they go out to fight.
Because the warriors are physically distant from the holy site, their prayers must bridge the geographic gap. The primary approach among commentators is that the soldiers achieve this by physically turning their faces toward Jerusalem and the Temple when they pray. However, this orientation is not merely a physical requirement. It carries a deep spiritual purpose. As they face the chosen city, the soldiers intentionally direct their hearts, ensuring their prayers ascend to heaven through Jerusalem and the house built for the name of God [מצודת דוד].