The biblical Israelites may have been high on a hallucinogenic plant when Moses brought the Ten Commandments down from Mount Sinai, according to a new study by an Israeli psychology professor.

Writing in the British journal Time and Mind, Benny Shanon  of Jerusalem's Hebrew University said two plants in the Sinai desert contain the same psychoactive molecules as those found in plants from which the powerful Amazonian hallucinogenic brew ayahuasca is prepared.

The thunder, lightning and blaring of a trumpet which the Book of Exodus says emanated from Mount Sinai could just have been the imaginings of a people in an "altered state of awareness", Shanon hypothesized.

"In advanced forms of ayahuasca inebriation, the seeing of light is accompanied by profound religious and spiritual feelings", Shanon wrote.

"On such occasions, one often feels that in seeing the light, one is encountering the ground of all Being ... many  identify this power as God."