Meditation on the law and word of God appears in Psalm 1, in Joshua 1, and again in Psalm 119.
In Psalms 1:2:
2 But his delight is in the law of the LORD; and in his law doth he meditate day and night.
In Joshua 1:8:
8 This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.
In Psalms 119:15:
15 I will meditate in thy precepts, and have respect unto thy ways.