Alexander Pope quotation

I have a copy of a letter written by the English author Matthew Henry Barker (1790-1846) in the early 1800's to a friend. Barker ends the letter thus: (the quotation marks are Barker's and the word I've given as Nay might be wrong, it's difficult to decipher the handwriting):

"God bless you my old boy!
Keep your weather eye up.
Nay he rules the winds and waves
Your sorrows quickly dry up"
Pope

I assume that Pope is Alexander Pope, but have been unable to confirm that this is a quotation from Alexander Pope, or identify the work. Any suggestions?