John Wesley on 1 Samuel 3:1

Before Eli - That is, under his inspection and direction. Word - The word of prophecy, or the revelation of God's will to and by the prophets. Precious - Rare or scarce, such things being most precious in mens' esteem, whereas common things are generally despised. Open vision - God did not impart his Mind by way of vision or revelation openly, or to any public person, to whom others might resort for satisfaction, though he might privately reveal himself to some pious persons for their particular direction. This is premised, as a reason why Samuel understood not, when God called him once or twice.