"I have no direct proof of this interpretation," and such proof cannot be expected, he says. However, "it seems logical that something was altered in people's consciousness.
Note, in Exodus, there is nothing in the immediate or broader context that suggests the Israelites partook of hallucinatory objects. Not only that, but:
1. The event is recorded as historical,
2. The people are said to have been sanctified for two days (pointing to their purity and consecration),
3. The sound was exceeding loud... so that ALL the people that were in the camp trembled (not just some... i.e., some who were hallucinating)
4. The assertion is that the children of Israel saw (or perceived) that God talked with them "from heaven", not through their own imaginations.
5. The account is referred to by others as both a historical and revelatory event.
6. The event is in perfect keeping with the rest of the unfolding of biblical revelation and redemption.
The point is this...rather than performing proper exegesis, one must come with their own presuppositions ...that this "cannot" mean what it seeks to say ... in order both to connive a theory that the Israelites were partaking of hallinatory plants (when one admits there is no evidence of that, nor can or should one suggest it to be proved).
Just as interesting, is that atheists delight in things of this nature as seen here.