The Testimony

To commemorate the miracle of manna, another miracle was preformed--the preservation of the manna:
And Moses said, This is the thing which the LORD commandeth, Fill an omer of it to be kept for your generations; that they may see the bread wherewith I have fed you in the wilderness, when I brought you forth from the land of Egypt. And Moses said unto Aaron, Take a pot, and put an omer full of manna therein, and lay it up before the LORD, to be kept for your generations. As the LORD commanded Moses, so Aaron laid it up before the Testimony, to be kept. (Exodus 16:32-34)

Exactly where was this manna kept? In "the Testimony." But just what does this mean? The Dake Annotated Reference Bible offers the following clarification, on page 112 of the Old Testament:

The Testimony (Ex. 16:34)
This refers to the tabernacle of worship, especially the ark of the testimony (v. 34; 25:22; 26:33-34; 30:6, 26; 31:7; 38:21; 39:35; 40:3, 5, 21; Num. 4:5; 7:89; Josh. 4:16).
The testimony here refers to the two tables of stone, the ten commandments-the sum of the whole law (Ex. 25:16, 21; 31:18; 32:15; 34:29; 40:20). It was considered the old testament or covenant (2 Cor. 3:6-15).
The tabernacle is called "the tabernacle of testimony" (Num. 1:50-53; 10:11) and "the tent of the testimony" (Num. 9:15). The ark itself is also called the testimony because it contained the covenant (Ex. 27:21; 30:36; Lev. 16:13; Num. 17:4, 10).
Any covenant or word of God is called a testimony because it testifies of God's revelation and provision of redemption in Christ (Ps. 19:7; 119:88; 132:12; Isa. 8:16, 20; 2 Cor. 1:6; 2:1; 2 Tim. 1:8; Rev. 1:2, 9; 12:17; 19:10). The real tabernacle, ark, and testimony from which Moses made his are in heaven (Heb. 8:5; 9:23; Rev. 11:19; 15:5). Various parts of the Word of God are called testimonies (Dt. 4:45; 6:17, 20; 1 Ki. 2:3; Ps. 119:2, 14, 22, 24, 31, 36, 46, 59, 79, 95, 99, 111, 119, 125, 129, 138, 144, 146, 152, 157, 167, 168). Testimonies are distinguished from commandments (2 Ki. 23:3; 1 Chr. 29:19; 2 Chr. 34:31; Neh. 9:34), His covenant (Ps. 25:10), ordinances (Ps. 99:7), and statutes (Jer. 44:23). All these are testimonies, but there are others besides these.

The ark and tabernacle weren't yet made when the manna was put into the pot. We must therefore believe that putting the manna before the testimony was after the ark was made; or believe there was some kind of tabernacle in Israel even before the one Moses patterned after heavenly things as he was instructed to do at Sinai. Israel surely had such a place--even Adam and his sons had one (Gen. 4:7, note); and Moses pitched a tabernacle outside the camp before he made the one at Sinai (Ex. 33:7-11). The one at Sinai was not set up until the first month of the second year after leaving Egypt (Ex. 40:2, 17) and it was placed inside the camp (Num. 2).

Potiphar and his wife
Israel "borrowing" from Egypt
The hardening of Pharaoh's Heart
The Glory of God in Moses' face
The Glory of the Lord
Living a Long Life
Sickness and Disease