  Prediction of the solar cycle is challenging but essential because it drives
space weather. Several predictions with varying amplitudes of the ongoing
Cycle~25 have been made. We show that an aspect of the Waldmeier effect (WE2),
i.e., a strong positive correlation between the rise rate and the amplitude of
the cycle, has a physical link with the build-up of the previous cycle's polar
field after its reversal. We find that the rise rate of the polar field is
highly correlated with the rise rate and the amplitude of the next solar cycle.
Thus, the prediction of the amplitude of the solar cycle can be made just a few
years after the reversal of the previous cycle's polar field, thereby extending
the scope of the solar cycle prediction to much earlier than the usual time.
Our prediction of Cycle 25 based on the rise rate of the previous polar field
is $137\pm 23$, which is quite close to the prediction $138\pm 26$ based on the
WE2 computed from the available 2 years sunspot data of the ongoing cycle.
