Here's the full stanza:
> Our two souls therefore, which are one, though I must go,
> Endure not yet a breach, but an expansion,
> Like gold to airy thinness beat,
> Whose soul sense in
> This tenuity spreads into thee.
The stanza is about the speaker and his beloved's souls being one, and how their love will not be broken by physical distance. The speaker uses the metaphor of gold being beaten thin to describe how their souls will become more interconnected despite the separation.
The "soul sense" is the ability of the soul to perceive and understand things beyond the physical world. By saying "whose soul sense in this tenuity spreads into thee," the speaker is saying that his soul, in its "airy thinness," can now perceive and understand his beloved's soul even more deeply than before.
Here's how we can interpret the meaning further:
* "Whose soul sense in": The possessive "whose" refers to the "airy thinness" of the gold, which symbolizes the soul's state. It's as if the soul's perception is becoming more refined and acute.
* "This tenuity spreads into thee": This line suggests that the speaker's expanded soul is now capable of reaching out and encompassing his beloved's soul.
Therefore, the phrase "Whose soul sense in" signifies a heightened spiritual awareness and connection that allows the speaker to experience a deeper understanding of his beloved's soul, even in their physical absence.