Exodus 25:16

“And thou shall put into the ark the testimony that I shall give thee.] Which was the principal use of it: by the “testimony” is meant the law, written on two tables of stone; so called, because it was a testification of the mind and will of God, what he would have done or omitted; and as the Israelites had declared their approbation of it, and assent unto it, and had promised obedience to it, therefore, should they transgress it, it would be a testimony against them: now this was put into the ark, and preserved there, (see <051001>Deuteronomy 10:1-5), which may signify that the law was in the heart of Christ, and which he undertook to fulfil, and with pleasure did it; that he is become the…”

“the testimony--that is, the two tables of stone, containing the ten commandments, and called "the testimony," because by it God did testify His sovereign authority over Israel as His people, His selection of them as the guardians of His will and worship, and His displeasure in the event of their transgressing His laws; while on their part, by receiving and depositing this law in its appointed place, they testified their acknowledgment of God's right to rule over them, and their submission to the authority of His law. The superb and elaborate style of the ark that contained "the testimony" was emblematic of the great treasure it held; in other words, the incomparable value and excellence of…”

“(compare Exodus 37:1-5). The ark is uniformly designated in Exodus the ark of the testimony. Elsewhere it is called the testimony, the ark of the covenant (most frequently in Deuteronomy and the other books of the Old Testament), the ark of the lord, the ark of god, the ark of the strength of the lord, and the holy ark. The ark of the covenant was the central point of the sanctuary. It was designed to contain the testimony Exodus 25:16; Exodus 40:20; Deuteronomy 31:26, that is, the tables of the divine law, the terms of the covenant between Yahweh and His people: and it was to support the mercy-seat with its cherubim, from between which He was to hold communion with them Exodus 25:22. On…”

“Exo 16:34, Exo 27:21, Exo 30:6, Exo 30:36, Exo 31:18, Exo 32:15, Exo 34:29, Exo 38:21; Num 17:4; Deu 10:2-5, Deu 31:26; Kg1 8:9; Kg2 11:12; Ch2 34:14, Ch2 34:15; Act 7:44; Rom 3:2; Heb 9:4 Exodus 25:17”

“Into this ark Moses was to put "the testimony" (העדת; cf. Exo 40:20). This is the name given to the two tables of stone, upon which the ten words spoken by God to the whole nation were written, and which Moses was to receive from God ( Exo 24:12). Because these ten words were the declaration of God upon the basis of which the covenant was concluded ( Exo 34:27-28; Deu 4:13; Deu 10:1-2), these tables were called the tables of testimony (ch. Exo 31:18; Exo 34:29), or tables of the covenant ( Deu 9:9; Deu 11:15). Exodus 25:17”