For there is not a word— Or, When there is not a word in my tongue, O Lord, thou knowest all. But Mudge renders it, For, before the word is in my tongue, behold, O Lord, thou knowest the whole of it; i.e. "Thou knowest the whole matter of what I am going to say, before the word is formed upon my tongue."
Related Commentaries of Psalms 139:4
Psalms 139:4
4 For there is not a word in my tongue, but, lo, O LORD, thou knowest it altogether.