Both Joshua 1:8 and Psalm 1:2 tell us that we have to meditate and dwell on the word of the Lord all the time. At ordinary times (i.e., other than the times when we are reading the Bible), we should meditate on the Lord's Word. We should learn to mold our thoughts according to the thoughts of the Bible. We should be meditating whether or not we are reading the Word. Romans 8:6 speaks of the "mind set on the spirit." This means that we should think on the spirit, and fix it on the spirit. This verse does not mean that we should set our mind on the spirit only, but that we should have a mind of the spirit. We should not just concentrate on the spirit, but should have a concentration that is of the spirit. In other words, whenever our mind turns, it should always turn to God's Word. No matter what the circumstances may be, our mind should always be fixed on God's Word. This is a matter not of artificial reminding but of spontaneous meditating. Ordinarily, our mind should be a mind that is set on the Word. Our mind should not be set on the Bible only when we are thinking about the Bible; it should be on the Bible even when we are not thinking about it. We should be inclined toward God's Word in a spontaneous way.
There are two sides to our meditation. On the one hand, we meditate when we read the Bible. On the other hand, we meditate at all times. When we are reading the Bible, our mind should be meditating on God's Word. But when we are not reading the Bible, we should also be actively exercising ourselves with our trained mind. It is not a matter of forcing ourselves to think about the Scriptures. The Holy Spirit will direct our thoughts in this direction, and it will become part of our habit. Once we develop such a habit, we will spontaneously become rich in the Lord. (Watchman Nee, How to Study the Bible p.86-87)
Watchman Nee presents an alternative side to meditation, one that does not demand intense concentration or patience or internal stirring, but an identity in the Word and the continuing process of the Holy Spirit renewing our mind and establishing us in the mind of Christ. In a world of quick hits and many distractions, it is comforting to know that the Holy Spirit is more energetic than the things around us vying for our attention. He aggressively and vivaciously plants scripture within our thoughts and heart. When we read and study, the Word is planted within us. The Holy Spirit sets it bubbling up within our mind and heart, creating a different king of meditation: a mind of the Spirit. I once heard a preacher say, just let your mind wander, wherever it goes, that's where your heart is. This also is meditation: a mind that wanders back to the Word.