After consulting his deity at the men's request, the priest acts as an advisor and a worker of wonders to deliver his response [מצודת דוד, מלבי״ם, ביאור שטיינזלץ]. He begins with a blessing of peace, which serves as a wish for a successful journey [מלבי״ם].
He then assures the men that their path is directly in front of God. The primary approach among commentators is that this statement is a promise of positive divine providence. It implies that their journey is constantly before God's eyes, and He will actively watch over them, help them, and ensure they reach their goal safely [מצודת דוד, רד״ק, מלבי״ם, ביאור שטיינזלץ]. Building on this idea, [רד״ק] adds that this divine help means God is effectively going ahead of them to prepare their way.
Offering a different perspective, [רש״י] takes a more critical view of the entire process of consulting idols. Rather than reading the priest's words as a guarantee of success, he explains that the statement simply means the outcome of the journey is known only to God. Because the idol used by the priest has no actual reality or power to predict the future, the true knowledge of what lies ahead rests exclusively with Him [רש״י].