Water into the bowl jet is supplied through the overflow tube that extends above the flapper. A tube from the top of the fill valve supplies water into the overflow tube when it is filling the tank after the flush.

Either your float valve is set too high and water is trickling from the tank into the overflow valve (the water should stop about 1/4 to 1/2 inch before it reaches the top of the overflow valve), or you have a slow leak at the flapper that is causing a momentary drop in the float valve which results in water from the valve to be delivered to the overflow tube.