Is Gematria (Hisab al-Jummal) forbidden or permissible (haram or halal)?

Using the Abjad numerals (Hisab al-Jummal) in history and similar fields is permissible, and scholars have used it without being censured. However, using it in forbidden matters, such as revealing the unseen or in magic, is prohibited, because a means to the forbidden is forbidden, as explicitly stated by Al-Qarafi and others.