found this on wiki...

"Christian meditation is a form of quiet (but not necessarily silent) contemplation often associated with prayer or scripture study. It is rooted in the Bible, which directs its readers to meditate. In Joshua 1:8, God commands his people to meditate on his word day and night to instill obedience. The psalmist says that "his delight is in the law of the Lord, and in his law he meditates day and night" (Psalm 1:2). The Bible mentions meditate or meditation twenty times."

http://en.wikipedia.org/wiki/Christian_meditation