Abulafia divided Kabbalah in two and put himself firmly on one side of the line. The Kabbalah of the sefirot, which everyone else was doing, he regarded as the lower path: a way of contemplating the structure of the divine world. The higher path was what he called the Kabbalah of names, and its aim was not understanding but prophecy, now, in the person doing it.
The method is technical and physical. The practitioner takes the letters of a divine name and permutes them systematically, in every possible order, chanting them aloud, coordinating each with a controlled breath and a specific movement of the head that traces the vowel. The mind is deliberately emptied of ordinary content by the sheer combinatorial load, and what he describes as the seals on the soul begin to loosen. He compares the effect to untying knots, and warns repeatedly about attempting it without preparation, because he had seen what happened to people who did.
The end state he describes is a union in which the knower, the known and the act of knowing become one, and the practitioner may hear a voice or see a human figure who turns out to be himself. He is candid that this is dangerous and that the tradition would rather it were not written down. He wrote it down anyway, in a very large number of manuals, which is the reason the technique survived.