Persistence in supplications has important impact in acceptance of supplication so that the caller achieves his objectives. This is an important point which all callers should take note of, because majority of people may not be able to achieve their aims just for reading their prayers and supplications for a time. For instance a sick person whose sickness is minor can treat his sickness once but those whose sickness is chronic needs long time treatment for its cure, the same apply to those having psychiatric or psychological sickness, peoples that are affected with this type of sickness whether chronic or not cannot subdued it with one supplication rather it is incumbent on him to take repetition of prayers till he is fully cure and relief of his sickness just like other physical sickness.
To this end as the physical sickness need repetition of treatment in order to see the impact of the drugs the same applies to any issues that fall into the scope of supplication, then it is necessary to make repetition of our prayer in order to see the impact of its acceptance.
Indeed, it is possible for some people to attain their ambition by offering supplication once but that is very rare and uncommon. It is not proper for other people to expect the acceptance of their prayers by just offering supplication for once. So repetition of supplication is one of the emphases laid by the infallible ones in their traditions (peace be on them).