Hastings' Dictionary of the Bible (1898)
TESTIMONY, TES'TIMONIES. Ps 119:88, Ps 119:99. These terms sometimes denote the whole revelation of God's will. They frequently occur in this sense in the above Psalm. They also refer to the tables of stone, which were part of the covenant between God and the people of Israel, Ex 25:16; and hence the ark in which they were deposited is called "the ark of the testimony." Ex 25:22. See Ark. The gospel is also called "the testimony" in 1 Cor 1:6;
Rev 1:2, and elsewhere. See Witness.