What is the criterion for the speed and efficacy of a Ruqyah Shar'iyyah's response to illnesses?

Raqqa (exorcism) with remembrances and verses is a Sunnah (definition), and it is a type of supplication. However, healing through it is not guaranteed, as the outcome may not occur due to the presence of impediments or the non-fulfillment of conditions. Allah may also delay healing for a wisdom. The quality of the ruqyah (definition) depends on the sincerity and truthfulness of the one performing it, and their use of legitimate incantations, such as supplication and remembrance.