Literally, woodenly translated, the 9th Word is: “Thou shalt not answer (‘anah) with/against your neighbor a false witness.”
The verb ‘anah is of interest, mainly because it is such an uninteresting word. Of the 300+ times it’s used in the Old Testament, the KJV translates it as “answer” 240-some times; the NASB typically renders it as “answer” or “reply.” The KJV translates it as “bear” only four times, in Exodus 20:16, Deuteronomy 5:18, Proverbs 25:18, and Job 16:8. It translates it as “witness” or “testify” some 14 times.
Without exception, the book of Genesis uses ‘anah to mean “answer” or reply. The verb assumes a conversational situation, either between two humans or between God and a human being (e.g., 18:27; 23:5, 10, 14; 27:37, 39; etc.).
The uses in Exodus are more varied and interesting. On two occasions Israel “answers” the Yahweh’s summons to be His people (19:8; 24:3), uses the bracket the cutting of the Sinai covenant. Yahweh “answers” Moses with thunder (19:19). Those are all consistent with the uses in Genesis.
Yet, the first use of ‘anah in Exodus veers in a different direction. After Israel crosses the sea, Moses leads them in the song of Moses (15:1-18). Then we’re told that Miriam and the women take up timbrels to dance and “answer them” with another chorus of the song (vv. 19-20). Who are “them”? How is the song an answer?
The answers aren’t clear, but there’s a similarly puzzling use later in Exodus. While Moses is on Sinai, he hears a sound from the foot of the mountain. Joshua thinks it’s the sound of war, but Moses hears something else. Woodenly, 32:18 is: “And he said, ‘There is not the voice of the answer (qol ‘anot) of triumph; there is not the voice of the answer (qol ‘anot) of defeat; a voice of the answer (qol ‘anot) I myself am hearing.”
That’s not an act of despair. There are passages where it’s fairly clear that ‘anah takes musical form. Numbers 21:17 tells us that Israel sang a song: “Spring up, well! ‘anah to it. The servants of Achish recognize David as the one of whom “they answer” as they dance (1 Samuel 21:11; cf. 29:5). Psalm 147:7 exhorts us to “Answer Yahweh with thanks,” which is parallel to “sing praise with the lyre.” Hosea promises a day when Israel will have vineyards so that she will ‘anah as in the days of her youth, when she came from Egypt.
We might say: Worship, including liturgical song, answers to a prior word. It’s the human echo to the Word who is with and is the Lord.
The uses of ‘anah in Exodus appear to be arranged in a roughly chiastic pattern:
A. Miriam answers at the sea, 15:21
B. The people answer: All that Yahweh commands, we will do, 19:8
C. Yahweh answers Moses with a sound like a trumpet, 19:19
D. Do not answer your neighbor with false witness, 20:16
C’? Do not answer a dispute to pervert justice, 23:2
B’. The people answer: All that Yahweh commands, we will do, 24:3
A’. The voice of answering before the golden calf, 32:18
Does any of this help with the usage in the 9th word? Perhaps we can draw these conclusions:
1) True or false witness is an “answer,” perhaps a reply to a summons (cf. Leviticus 5:1), perhaps a response to a situation that of which the witness has knowledge. Testimony is one pole of a dialogue.
2) That is consistent with the liturgical uses of ‘anah. Perhaps the 9th word stretches to encompass false worship or confession or evangelistic witness.
3) If the Ten Words are organized in parallel sets of five (as James Jordan has suggested), the 9th matches the 4th. There is some link between consecrating the day of ceasing and answering truly and faithfully. Perhaps this: Sabbath is a right answer to Yahweh, an ordering of time that answers truly to creation and Exodus.