Musnad Ahmad 33:663

Hujayn and Yunus narrated to us, they said: Al-Layth ibn Sa’d narrated to us, from Abu al-Zubayr, from Jabir ibn Abdullah, from the Messenger of Allah (may Allah bless him and grant him peace) that he said: "If one of you sees a vision that he dislikes, let him spit to his left three times—and Yunus said: let him blow (spit) three times—and let him seek refuge in Allah from the Shaytan three times, and let him turn over from the side he was on."