Instructions are given to Isaiah and to Judah.
Verses 12–13: Judah must not rely on alliances with foreign powers for safety but rely on the Lord and reverence him.
Verses 14–15: The Lord can be a sanctuary, but he can also be a stone of stumbling, a rock of offense, for both houses of Israel (Israel and Judah). For similar descriptions, see the writings of Peter, Paul, and Jacob: 1 Peter 2:8; Romans 9:33; 1 Corinthians 1:23; and Jacob 4:15.
Verse 16: The testimony is the Prophets, and the law is the Torah, or five books of Moses. Together the testimony and the law constitute the scriptures (see also v. 20). Isaiah was to write down and seal up his own witness account.
Verses 17–18: Isaiah trusted in the Lord. He and his family were “for signs and for wonders” to the house of Israel; they constituted a message from God in the form of a similitude or a type. Just as Abraham and Isaac were types of the Father and Son, so Hosea and his unfaithful wife were types of the Lord and his unfaithful people. Isaiah signified that salvation was in Jehovah; Shearjashub meant that a remnant of Judah would return following the chastisement of exile; and Maher-shalal-hash-baz foreshadowed the imminent and speedy destruction of a large part of Israel.
“The Lord of Hosts … dwelleth in Mount Zion”—the house of the Lord was on Mount Zion, or the Temple Mount.