High on Mount Sinai, Moses was on psychedelic drugs when he heard God deliver the Ten Commandments, an Israeli researcher claimed in a study published this week.

Such mind-altering substances formed an integral part of the religious rites of Israelites in biblical times, Benny Shanon, a professor of cognitive psychology at the Hebrew University of Jerusalem wrote in the Time and Mind journal of philosophy.

"As far Moses on Mount Sinai is concerned, it was either a supernatural cosmic event, which I don't believe, or a legend, which I don't believe either, or finally, and this is very probable, an event that joined Moses and the people of Israel under the effect of narcotics," Shanon told Israeli public radio on Tuesday.

Moses was probably also on drugs when he saw the "burning bush," suggested Shanon, who said he himself has dabbled with such substances.

"The Bible says people see sounds, and that is a clasic phenomenon," he said citing the example of religious ceremonies in the Amazon in which drugs are used that induce people to "see music."

He mentioned his own experience when he used ayahuasca, a powerful psychotropic plant, during a religious ceremony in Brazil's Amazon forest in 1991. "I experienced visions that had spiritual-religious connotations," Shanon said.

He said the psychedelic effects of ayahuasca were comparable to those produced by concoctions based on bark of the acacia tree, that is frequently mentioned in the Bible.