Zechariah 8:9
Thus saith the Lord of hosts; Let your hands be strong, ye that hear in these days these words by the mouth of the prophets, which were in the day that the foundation of the house of the Lord of hosts was laid, that the temple might be built.
Cross-references
Zechariah 8:11 immediately follows with a promise of blessing, contrasting the former days—direct continuation of the same prophecy.
Joshua 1:6 gives the same 'Be strong and courageous' command to Joshua for entering the land, paralleling the temple builders' encouragement.
1 Chronicles 22:13 records David charging Solomon to be strong and courageous for building the temple, directly echoing this temple-building exhortation.
1 Chronicles 28:20 has David again telling Solomon 'Be strong and courageous' for the temple work, reinforcing the same call with a promise of God's presence.
Ezra 5:1-2 describes Zechariah and Haggai prophesying and the temple rebuilding beginning, providing the historical fulfillment of the call here.
Ezra 5:2 shows Zerubbabel and Jeshua building the temple with prophets helping—the exact context Zechariah 8:9 addresses.
Haggai 1:1 introduces Haggai, one of the prophets whose words Zechariah 8:9 says the people were hearing.
Haggai 1:12 records the people obeying Haggai's message—the same prophetic words Zechariah 8:9 references for encouragement.
Haggai 2:4-9 directly commands 'Be strong' to Zerubbabel, Joshua, and all the people for temple work, with the same historical and thematic setting.
Haggai 2:18 explicitly marks 'the day the foundation of the Lord's temple was laid'—the same starting point Zechariah 8:9 uses.
Isaiah 35:4 encourages the anxious to 'Be strong; fear not' with a promise of salvation, similar in phrasing but eschatological rather than temple-focused.