Psalm 4:4 Amplified Bible (AMP)
Tremble [with anger or fear], and do not sin;
Meditate in your heart upon your bed and be still [reflect on your sin and repent of your rebellion]. Selah.
Psalm 4:4 New International Version (NIV)
4 Tremble and do not sin;
when you are on your beds,
search your hearts and be silent.