What does Prince Escalus mean with "See what a scourge is laid upon your hate/That heaven finds means to kill your joy with love"?Romeo and Juliet...

The Prince says this in the very end of Act 5. He is
talking to both Montague and the Capulets. He is telling them how wrong it is that they
have been warring with each other for so long. He is reminding them that Heaven or God
has now had to intervene and give them real consequences that will make them consider
changing their behaviors. The consequence for each of them is the death of their
children (their joy). Had they not been at war with each other, none of this ever would
have happened. Ironically, their hate was defeated by love. The Prince pointed out that
their joy in life was killed by love, Romeo and Juliet's love for each other which could
not be quenched legally in front of their parents. The hiding that the kids had to do
helped lead to these deaths.