Any place where it makes an analogy between one matter and another matter, the Torah will not mention explicitly that the law applies for both matters. And when the Torah does mention that the law applies for both matters explicitly, the analogy is superfluous, and there will be a homiletical interpretation.

And it is not the way of the Scripture to deduce the law for the previous from the law for the subsequent, only the law for the subsequent from the law for the previous.