The Discourse on Hindrances : AN 9.64
"Monks, there are these five hindrances. Which five? Sensual desire as a hindrance, ill will as a hindrance, sloth & drowsiness as a hindrance, restlessness & anxiety as a hindrance, and uncertainty as a hindrance. These are the five hindrances.
"To abandon these five hindrances, one should develop the four frames of reference. Which four? There is the case where a monk remains focused on the body in & of itself — ardent, alert, & mindful — putting aside greed & distress with reference to the world. He remains focused on feelings in & of themselves... mind in & of itself... mental qualities in & of themselves — ardent, alert, & mindful — putting aside greed & distress with reference to the world. To abandon the five hindrances, one should develop these four frames of reference."