Whither the tribes - The twelve tribes of the children of Israel.
Go up - To the great feasts and festivals of the nation. See Exodus 23:17. This language of going up is such as would be used anywhere respecting the capital of a nation - as it is now of London; but it was literally true of Jerusalem, since it was elevated far above most parts of the land.
The tribes of the Lord, unto the testimony of Israel - The “ark of testimony;” the ark within which were the tables of stone, containing the law considered as God’s testimony or witnessing as to justice, right, equity, duty, truth. See Exodus 16:34; Exodus 25:16, Exodus 25:21; Exodus 40:3, Exodus 40:20; Exodus 30:6, Exodus 30:36; Exodus 31:18.
To give thanks unto the name of the Lord - To worship Yahweh - the name often being put for the Being himself. A main part of Hebrew worship was praise, and hence, this is often put for the whole of worship.