Wahi (Arabic: وحي‎ waḥy, IPA: [waħj]) is the Arabic word for revelation. In Islamic context, it refers to the revelations of God (Arabic: Allah) to his prophets, for all humankind. In Islam, the Qur'an is considered a wahi given to Muhammad.

The word awha (أوحى awḥá) occurs in a number of shades of meaning in the Qur'an, each of them indicating the main underlying idea of directing or guiding someone. The word 'wahy' (revelation) is derived from awha.

Muhammad is reported to have had mysterious seizures at the moments of inspiration. Welch, a scholar of Islamic studies, in Encyclopaedia of Islam states that the graphic descriptions of Muhammad's condition at these moments may be regarded as genuine, since they are unlikely to have been invented by later Muslims. According to Welch, these seizures should have been the most convincing evidence for the superhuman origin of Muhammad's inspirations for people around him. Muhammad's enemies however accused him as one possessed, a soothsayer, or a magician since these experiences made an impression similar to those soothsayer figures well known in ancient Arabia. Welch states it remains uncertain whether Muhammad had such experiences before he began to see himself as a prophet and if so how long did he have such experiences.