14 May the words of my mouth and the meditation of my heart
be pleasing in your sight,
O LORD, my Rock and my Redeemer.
You are what you eat is the old adage. But Biblically there is a much better one. You are what you say. Here in the Psalms is a prayer to the Lord that our words and our thoughts would be pleasing to God. This is the same idea as what Jesus told His disciples that the words that come out of our mouths show the contents of our hearts(Matthew 15). So we could even take it a step deeper and say, you are what you think about (meditate on if you will). It is why the Psalmist says in Psalm 119:37 – Turn my eyes away from worthless things; preserve my life according to your word.