Ibn 'Abbas narrated that the Prophet (s.a.w) said:
"Whoever lies about having a dream, he will be required to knot two barely kernels together on the Day Of Judgment., and he will never be able to knot them together." (RU)
English reference (RU): Vol. 4, Book 8, Hadith 2283 (RU)
Arabic reference (RU): Book 34, Hadith 2452 (RU)