Meditation is scriptural. Old Testament, New Testament, it's all throughout. In the Psalms, King David even comments on meditation often.

But, the practice of slowing ourselves down, "chewing" on God's Word and allowing it to refine our thinking and doing, is not something Christ-followers do today. The world demands busy from us. So, we have to be intentional about slowing down and spending time meditating on what He is saying to us.