The word in Hebrew that is translated as testimony is עֵדוּת (eduth), and is derived from עֵדe (ed—note that both of these words are pronounced with an “ae” sound in English).  Both words carry similar meanings, though the connotations vary somewhat in terms of how they are used.

The first word, עֵדוּת e (eduth), refers to a witness or testimony, but is normally used in terms of legally binding stipulations or laws.  The Tabernacle is, for example, called the Tabernacle of Testimony (Numbers 17:4) because they were the home of the tablets of the Ten Commandments.  This becomes very pronounced when you get to verse 10 of the same chapter, for Moses is told to put the staff of Aaron before the testimony — ultimately the staff then was kept with the 10 commandments (Hebrews 9:4).  

Thus, when Psalm 119 speaks of testimony in this sense, it can be said to be speaking of the Moral Law (10 Commandments). Of course, all of God’s Law — all of the Scriptures even — are connected with the Ten Commandments.  This word testimony is found 9 times in the 119^th psalm (which should tell us something right there), and is located in verses 14, 31, 36, 88, 99, 111, 129, 144, and 157.

The second word עֵד (ed), is a massively important word in Hebrew and is found 118 times in the Old Testament even though it is not explicitly found in Psalm 119.  It refers to the idea of witness in much the same way as the New Testament Greek term μαρτυρία (marturia—from which we get the term “martyr”) is used.  This word refers to that witness which confirms the truth to be so.  This is one’s testimony of faith before men, for example, as well as being a testimony in a court of law.

The connection between these two words is found in the concept of the covenant of God.  God’s covenant with his people is his  עֵד (ed), but this עֵד (ed) contains stipulations for those that would be in covenant with our Lord and King.  Those stipulations are the עֵדוּת e (eduth) of God.  

What is also worth noting is that another word that is derived from עֵד (ed) is the term עֵדַה (edah), which means “congregation,” referring to a gathering of God’s people.  God’s people are those that he has put into relationship with himself through his covenant, his עֵד (ed), and regulates through his עֵדוּת e (eduth).  All very closely connected.  This word is found 14 times in Psalm 119 (vs. 2, 22, 24, 46, 59, 79, 95, 119, 125, 138, 146, 152, 167, 168).  So closely are these words and ideas related that in most, if not all cases, when Psalm 119 is translated into English, they have translated it as “testimony” rather than congregation.  This is probably a little misleading in the crossover to English, but at the same time, in the context of the Psalm, it appears that the Psalmist is doing much the same thing—wedding together these ideas.  Or, to put it another way, the presence of the covenant people of God are God’s testimony to his own covenant faithfulness—his חֶסֶד (chesed—pronounced with a hard “ch” like in “Loch Ness”).  The word חֶסֶד (chesed) is variously translated in our English Bibles, but refers to the covenantal faithfulness of God in spite of our covenantal unfaithfulness, and is found 7 times in Psalm 119 (vs. 41, 64, 76, 88, 124, 149, 159) and is often translated as “steadfast love” or “mercy.”

With this in mind, permit me to digress to Deuteronomy 6:4 for a moment, commonly called “the Shema” in Hebrew circles.  The bulk of the book of Deuteronomy consists of Moses’ sermonic expositions of the Ten Commandments, forming a Constitution for the people of Israel.  With this in mind, the Shema functions essentially as the preamble to the constitution for the people.  In fact, in Judaism, Deuteronomy 6:4 is considered to be the single most important verse in the Bible and the very language that defines them as a people—giving them their national identity.  It establishes their relationship with God as a covenant people and reminds them that they are a people who have been given a name, loved as such by their God.  It is the first prayer that the faithful Hebrew prays when he wakes in the morning and the last prayer he prays before he goes to bed at night.  It is also chanted at the beginning of a traditional synagogue service.  What is especially interesting is the way it is written in the Hebrew Bible:

 שְׁמַע יִשְׂרָאֵל יְהוָה אֱלֹהינוּ יְהוָה אֶהָד

Note that the last letter of the first and last words have been written larger and in bold print.  These two letters, when taken out of the verse spell, עֵד (ed) — or witness.  In other words, the Shema itself is the witness of the Jewish people to their God, just as the covenant is God’s עֵד (ed) to his people.  Lastly, if you reverse the letters of עֵד (ed), you end up with the word דֵּעַ (de’a), which means “knowledge.”  Just as fear of the Lord is the beginning of all wisdom (Psalm 111:10), so too is all true knowledge rooted in the covenant of God.  Any pursuit of knowledge apart from God’s revelation through his covenant is vanity, Solomon reminds us in Ecclesiastes.

Covenant is, as we know, the context in which God interacts with his people.  On the very first day that Adam was alive and placed in the Garden God established his covenant with Adam and set before Adam the עֵדוּת e (eduth) of the covenant—don’t eat lest you will die-die.  The punishments given out after the fall are the consequences of their failure to fulfill the covenant.  Genesis 3:15, though reminds us that a Messiah is coming who will redeem his people from bondage to the one who led them into sin.  Genesis 15 provides us with a foretaste of what would happen to this divine Messiah, though.  In the context, God is confirming his covenant with Abraham and Abraham is sent to divide up the animals and separate them creating a bloody path to walk through.  In ancient times, when covenants were made between Kings and their Vassals, they would divide up a group of animals like this, and then the Vassal, as a pledge of faithfulness to the covenant, would walk through the middle of the line of animals as if to say, “if I don’t fulfill my part of the covenant, may what happened to these animals happen to me also.”  Now, some have suggested that there may be evidence that both the king and vassal walked through this line, but the evidence is varied and this proposition makes little sense as the vassal had no power to enforce this commitment upon the king, where the king certainly had the power to enforce it upon his vassal.

Either way, what is significant is that Abraham should have walked through the bloody pathway, but God puts him into a deep sleep (not unlike the sleep that God put Adam into before he took out his rib to form Eve), and God walked through the bloody pathway in Abraham’s stead.  God was saying to Abraham, I will be your covenant mediator and representative for this covenant.  If you or your line fail to keep this covenant, may what happened to these animals happen to me as well.  And that is exactly what took place on the cross of Calvary.  Jesus fulfilled what God promised, bloody and bruised, because we could not be faithful to the עֵדוּת e (eduth) of God’s covenant.

In the context of Psalm 119, the psalmist completely understands that for one to be truly blameless and righteous before the Lord, one must first submit his life to the testimonies of our God—to the עֵדוּת e (eduth) of God’s covenant.  Thus, he sets the Law before him as a guide and instructor.  We must understand that while the psalmist speaks at times of being blameless before his accusers, this is not to be interpreted in terms of a form of human self-righteousness.  Instead, he also understands, as Abraham understood, that his redemption would be paid for by another—by God himself through the promised Messiah, and that his personal righteousness was based, through faith, in the coming of the promised one.  At the same time, he understands the thrust of what Paul would say in Romans 6:1-2.  In light of that, the psalmist both begins and ends the psalm focused on remembering and obeying the Law of the Lord.