What is meant by the concept of number and the rule "that number has no meaning"?

The concept of mafhum al-mukhalafah (inference by contra-distinction) is the establishment of the opposite of a stated ruling for an unstated case. It is considered an authoritative proof (hujjah) by the Malikis, Shafi'is, and Hanbalis. Among its categories is mafhum al-'adad (inference from number), which is the conditioning of a ruling by a specific number, such as in the verse: "Flog them with eighty stripes" (An-Nur: 4). This has been affirmed by Ahmad, Malik, Dawud, and some Shafi'is, in contrast to the Hanafis, Mu'tazilah, and Ash'aris. The view that it is an authoritative proof is sounder, so that the specification does not become devoid of benefit, unless the number is used for hyperbole, as in the verse: "If you ask forgiveness for them seventy times, Allah will not forgive them" (At-Tawbah: 80).