Looking over the entirety of Psalm 119, the writer refers to God's law in nearly every verse, or God's Word, commandments, or directions.
The immediate response we may offer to this statement is that God wants us to meditate on the Ten Commandments.
Yet sections of Psalm 119 suggest otherwise:
DALETH. My soul cleaveth unto the dust: quicken thou me according to thy word." (Psalm 119: 25)
"Behold, I have longed after thy precepts: quicken me in thy righteousness." (Psalm 119: 40)
Now, the Ten Commandments is a ministration of death and condemnation, not life and righteousness:
"But if the ministration of death, written and engraven in stones, was glorious, so that the children of Israel could not stedfastly behold the face of Moses for the glory of his countenance; which glory was to be done away: 8How shall not the ministration of the spirit be rather glorious? 9For if the ministration of condemnation be glory, much more doth the ministration of righteousness exceed in glory. 10For even that which was made glorious had no glory in this respect, by reason of the glory that excelleth. 11For if that which is done away was glorious, much more that which remaineth is glorious." (2 Corinthians 3: 7-11)
We cannot find life in the Ten Commandments, in the Old Covenant.
In fact, Jesus fulfilled the law, which was meant as a testimony our dead-in-trespasses state:
"19Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God. 20Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin." (Romans 3: 19-20)
"20Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound: 21That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord." (Romans 5: 20-21)
"13And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having forgiven you all trespasses; 14Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross; 15And having spoiled principalities and powers, he made a shew of them openly, triumphing over them in it." (Colossians 2: 13-15)
Notice that the verses in Colossians, Paul writes about "the ordinances against us, contrary to us". He's writing about the Ten Commandments. They do not give us life, they do not minister righteousness to anyone.
So, we no longer meditate on the Ten Commandments or the Old Covenant to have life, because the law has been fulfilled in Christ.