When the magus proclaims "abracadabra", it is after the fact, not before. Thus the translation "I shall create", in the future tense, would be inappropriate. Instead, consider "abra" to be in the past. "It has passed (i.e., taken place)." With the rest of Cohen's translation, the whole phrase now makes sense; the speaker assures the listener that the incantation has been effective - and collects the fee for the service.
10 arrested at Israeli Arab protest in Ramle (Haaretz)
from the article: Word of the Day / Abracadabra: Be careful what you wish for