YOU SAID:

And those who disbelieve say of those who believe, "If it had truly been good, they would not have preceded us to it." And when they are not guided by it, they will say, "This is an ancient falsehood

INTO JAPANESE

信じない者は信仰する者に言う。「もしこの（クルアーンを信じること）が良いのであれば，かれらがわたしたちに，先んじる筈はない。」またかれらはそれによって，導きなどを受けないのであるとして，「これは昔の作り話しです。」と言う。

BACK INTO ENGLISH

And the disbelievers said regarding the Muslims, “If there were any good in it, the Muslims would not have surpassed us in achieving it!”; and since they did not receive guidance with it, they will now say, “This is an old slander.”

INTO JAPANESE

信じない者は信仰する者に言う。「もしこの（クルアーンを信じること）が良いのであれば，かれらがわたしたちに，先んじる筈はない。」またかれらはそれによって，導きなどを受けないのであるとして，「これは昔の作り話しです。」と言う。

BACK INTO ENGLISH

And the disbelievers said regarding the Muslims, “If there were any good in it, the Muslims would not have surpassed us in achieving it!”; and since they did not receive guidance with it, they will now say, “This is an old slander.”