Nod

• pr a nod is as good as a wink to a blind horse: "However obvious a hint or suggestion may be, it is useless if the other person is unable to see it" (E. C. Brewer, Dictionary of Phrase and Fable)

• The Prophet Mohammed: "Prayer is better than sleep" → "a nod to the nabir" means "a prayer to the Prophet," and wink = sleep

• Land of Nod: the realm of sleep → Genesis 4:16: "And Cain went out from the presence of the Lord, and dwelt in the land of Nod, on the east of Eden." → Jonathan Swift, A Complete Collection of Genteel and Ingenious Conversation, According to the Most Polite Mode and Method Now Used at Court, and in the Best Companies of England. In Three Dialogues. By Simon Wagstaff, Esq. [pseud] (London 1738)

• nod off: to fall asleep → wink, meaning a short spell of sleep