Albert Barnes Commentary Psalms 119:48

"I will lift up my hands also unto thy commandments, which I have loved; And I will meditate on thy statutes. ZAYIN." — Psalms 119:48 (ASV)

My hands also I will lift up to your commandments ... - As an expression of delight or rejoicing, as people lift up their hands with their voice when they give expression to joy. It denotes a high degree of joy that leads to an outward expression. This is not merely the joy found in calm contemplation, but rather a joy where the heart is full and finds outward expression.

And I will meditate in your statutes - See the notes at Psalms 1:2. I will indicate my joy—my happiness—in your commandments in every way possible; by outward expressions and by deep and calm contemplation when I am alone; in my daily activities, in solitude, in the night-watches. This is always indicative of true religion.