Nehemiah 2:18 And I told them of the hand of my God that had been upon me for good, and also of the words that the king had spoken to me. And they said, “Let us rise up and build.” So they strengthened their hands for the good work. (ESV)
When can God's people move forward to do the work cut out for them? In Nehemiah's case, the same Persian king that had previously stopped the reconstruction of the city wall now ordered the resumption. To many readers, this was evidence that God's hand was now supporting their work.
Previously, their enemies weakened their hands (Ezra 4:4). But now, God's people strengthened their hands for the good, i.e., for the good work to continue. First, they resolved to continue building. Then, secondly, they did what they resolved.
God had promised restoration for the Jewish people of Nehemiah's time. Now, their own leaders (Ezra & Nehemiah) also gave them encouragement. We see the encouragement of God to Nehemiah now being transferred to the people, leading them to encourage themselves to continue the rebuilding.
The ESV translated the phrase as "Let us rise up and build", i.e., the people encouraged themselves for the good work or cause. What are you doing, or saying, that is contributing to the atmosphere to continue to build? Would you say something to strengthen the hands of others, not weaken them, as they continue God's calling in the place that God had placed them?