(4) For there is not . . .--This has been understood in two ways:--

My tongue cannot utter a word which thou dost not altogether know.

or,

Before my tongue can utter a word thou knowest it altogether.

Verse 4. - For there is not a word in my tongue, but, lo, O Lord, thou knowest it altogether. What has been already said of deeds and thoughts is now extended to "words." God hears every word we speak.

139:1-6 God has perfect knowledge of us, and all our thoughts and actions are open before him. It is more profitable to meditate on Divine truths, applying them to our own cases, and with hearts lifted to God in prayer, than with a curious or disputing frame of mind. That God knows all things, is omniscient; that he is every where, is omnipresent; are truths acknowledged by all, yet they are seldom rightly believed in by mankind. God takes strict notice of every step we take, every right step and every by step. He knows what rule we walk by, what end we walk toward, what company we walk with. When I am withdrawn from all company, thou knowest what I have in my heart. There is not a vain word, not a good word, but thou knowest from what thought it came, and with what design it was uttered. Wherever we are, we are under the eye and hand of God. We cannot by searching find how God searches us out; nor do we know how we are known. Such thoughts should restrain us from sin.For there is not a word in my tongue,.... Expressed by it or upon it, just ready to be spoken; or, as the Targum,

"when there is no word in my tongue:''

so Aben Ezra,

"before it was perfect in my tongue:''

before it is formed there; while it is in the mind, and not expressed, and even before that;

but, lo, O Lord, thou knowest it altogether; the whole of it, from whence it springs; the reason of it, what is designed, or the ends to be answered by it. The Lord knows the good words of his people, which they speak to him in prayer, even before and while they are speaking them; and what they say to one another in private conversation, Isaiah 65:24. See an instance of words known by Christ before spoken, in Luke 19:31.