"Best of Wives and Best of Women" is the 21st song of Act Two of Hamilton, and the 44th song of the overall musical.
Before dawn of the duel between himself and Burr, Alexander pauses by the door and bids farewell to Eliza. He lovingly compliments her, calling her the "best of wives and best of women", before setting off to the site of the duel in Weehawken, New Jersey.
This line, best of wives and best of women, was on the dedication page of Ron Chernow's book, which inspired Hamilton. It originates Hamilton's farewell letter to Eliza, detailing information of his death by the hand of Burr. He signs the letter with
'Adieu best of wives and best of Women. Embrace all my darling Children for me.