Hi, Jesset! These are the sections I would focus on while considering your answer.
Thy spirit is around,
Quickening the restless mass that sweeps along;
And this eternal sound--
Voices and footfalls of the numberless throng--
Like the resounding sea,
Or like the rainy tempest, speaks of thee.
Here, the poet speaks to God's spirit within a city crowd. Notice the words "eternal" and "resounding," both of which are often used in the context of religion and to describe an awestruck state. In addition, the poet speaks about the crowd the way someone might describe nature, referencing a "sea" or "tempest." This demonstrates that the poet believes city life holds the same power as the natural world to convey a sense of God's presence.
The quiet of that moment too is thine;
It breathes of him who keeps
The vast and helpless city while it sleeps.
In contrast to the previous section, this stanza describes a sense of God in rare moments of quiet within the city. The poet asserts that God is watching over the city as people rest, protecting it, and guarding the "helpless" individuals who live there.
Let me know if you have any questions!