Wink

• wink: a short spell of sleep; a hint → nod

• a nod is as good as a wink to a blind horse: (proverb) "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)

• Prayer is better than sleep: one of the stanzas of the adhan, or Islamic call to prayer; it is used only by Sunni Muslms and only before the first prayers of the day at dawn; it is attributed to one of Mohammed's Sahabah (companions), a freed Ethiopian slave by the name of Bilal ibn Ribah → "a nod to the nabir" = "a prayer to the Prophet," and wink = sleep
  • Wikipedia