Passage
the foundations of the wall of the city [were] adorned with every precious stone: the first foundation, jasper; the second, sapphire; the third, chalcedony; the fourth, emerald;
the foundations of the wall of the city [were] adorned with every precious stone: the first foundation, jasper; the second, sapphire; the third, chalcedony; the fourth, emerald;
Revelation 21:17 And he measured its wall, a hundred [and] forty-four cubits, [a] man's measure, that is, [the] angel's.
Revelation 21:18 And the building of its wall [was] jasper; and the city pure gold, like pure glass:
Revelation 21:19 the foundations of the wall of the city [were] adorned with every precious stone: the first foundation, jasper; the second, sapphire; the third, chalcedony; the fourth, emerald;
Revelation 21:20 the fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, topaz; the tenth, chrysoprasus; the eleventh, jacinth; the twelfth, amethyst.
Revelation 21:21 And the twelve gates, twelve pearls; each one of the gates, respectively, was of one pearl; and the street of the city pure gold, as transparent glass.
The verse centers on "foundations", "wall", "city", "adorned", "precious", "stone", and "first". It is saying that the verse draws attention to "foundations" and "wall", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 18's "And the building of its wall was..." into verse 20's "the fifth sardonyx the sixth sardius the...", so "foundations" and "wall" belong inside that flow. In Revelation context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "foundations" and "wall" with trust shaped by these words, not by a vague optimism outside the passage.