MACBETH: If we should fail —

LADY MACBETH: We fail!
But screw your courage to the sticking-place,
And we’ll not fail.

William Shakespeare (1564-1616) English dramatist and poet

Macbeth, Act 1, sc. 7, l. 68ff (1.7.68-71) (1606)
    (Source)

The sticking-place on a crossbow was where the bowstring was screwed or wound to prior to its bolt being shot.

The line was most famously revived by Howard Ashman in the lyrics to "The Mob Song [Kill the Beast]" in Beauty and the Beast (1991). Lin-Manuel Miranda also included the line (amidst many other Macbeth references) in Hamilton (2015), in the song "Take a Break."