1 Samuel 3:1 (NKJV)
There are some things that are rare and precious and some things that are very common. Gold is something that can be difficult to find, it is rare and that makes it more valuable, it is even called a precious metal. But dirt and grass are found in so many places that they are considered common and not rare or valuable. While people do not handle dirt and grass very often, they are still not considered rare or valuable things, dirt and grass are easily available and therefore common.
In 1 Samuel we see that when God began to speak to Samuel, Samuel thought it was Eli the priest who was speaking to him. Samuel did not yet know God or God's voice and Eli himself did not realize it was God speaking to Samuel. There was no widespread revelation of God's Word at this time, it was rare and so it was precious. Although God's people already had the first five books of the Old Testament, they had gotten away from God and His Word, so when a prophet spoke for God it was a rare thing and people considered that precious.
Today we are very blessed to have God's written Word, the Bible, easily available to us. But just because something is easily available does not mean it is widely used. And because God's Word is so readily available, people do not often consider God's Word as valuable and precious as they would something made of gold. Don't let a revelation of God's Word be rare to you, put the proper value on God's Word, treat it as precious as it really is and make it a common practice to spend time with God and His Word every day.