Answer:
1. The thirst that from the soul doth rise 'Repeated sound: /θ/ (voiced th)
2. Doth ask a drink divine 'Repeated sound: /d/'
3. 'Since when it grows, and smells, I swear...'Repeated sound: /s/
Explanation:
There is similarity in the first letters of closely related words.
Drink to me only with thine eyes,
    And I will pledge with mine.
Or leave a kiss but in the cup,
    And I’ll not look for wine.
The thirst that from the soul doth rise
    Doth ask a drink divine.
But might I of Jove’s nectar sup,
    I would not change for thine.
I sent thee late a rosy wreath,
    Not so much honoring thee
As giving it a hope, that there
    It could not withered be.
But thou thereon didst only breathe,
    And sent’st it back to me.
Since when it grows, and smells, I swear,
    Not of itself, but thee.
