Raḥmānān (Musnad: 𐩧𐩢𐩣𐩬𐩬 rḥmnn, "the Merciful") was an epithet and theonym predominantly used to refer to a singular, monotheistic God from the fourth to sixth centuries in South Arabia (though the term originates much earlier in Syria), beginning when the ruling class of the Himyarite Kingdom converted to Judaism and replacing invocations to polytheistic religions.
During the reign of the Christian Himyarite king Sumyafa Ashwa, Jesus was referred to as the son of Raḥmānān.
[2][3][4] The earliest known usage of the term is found in a polytheistic bilingual inscription from northeastern Syria written in Akkadian and Aramaic dedicated to the Aramean god Hadad.
Worship of the "Merciful One" (rḥmnn), under Mesopotamian cultural influence, became widespread in Syria in the first centuries AD.
[5] In the fourth century, the conversion of the ruling class of the Himyarite Kingdom to Judaism involved the replacement of all polytheistic invocations in inscriptions to references to the one God.
[9] In total, extant Late Sabaic inscriptions use the term Raḥmānān 58 times, none of which can be labelled as pagan or polytheistic.
The entry of the term al-Raḥmān into Old Arabic likely predates the Quran, as there is at least some pre-Islamic poetry using the phrase that appears to be authentic.
[12] Although Rahmanan was once its own name for the deity in South Arabia, and is sometimes used as such in the Quran, by its final redaction it had become an adjective modifying the word "God" as "the merciful".
[13] The lengthier Quranic phrase al-rahman al-rahim ("The Merciful, the Compassionate") is likely related to Himyaritic inscriptions referring to rahmanan metrahim (with the same meaning).
One example may be found in the Jabal Dabub inscription, which opens with reads "in the name of Allah, al-Rahman, al-Rahim, Lord of the heavens".