In the bible when God spoke to people in the old testament
it was in clouds of smoke after burning incense allot of times,and Rastafarians believe that this as well as the fact that it says something to the effect, (and the light did shine on their face from the glory of God) kinda like when people get squint eyed from smoking cannabis,might indicated the inadvertent use of cannabis to heighten their spiritual feeling.
There is also many other things in the bible including one of the ingredients in the holy anointing oil that they feel indicate cannabis use.

To any with knowledge of this: What are your feelings?