It is the variety thought to underlie the Quranic Consonantal Text (QCT) and in its later iteration was the prestige spoken and written register of Arabic in the Umayyad Caliphate.
The QCT along with the papyri of the first century after the Islamic conquests attest a form with an l-element between the demonstrative base and the distal particle, producing from the original proximal set ḏālika and tilka.
[6] Here is an example of reconstructed Old Hejazi side-by-side with its classicized form, with remarks on phonology: 1) ṭāhā 2) mā ʔanzalnā ʕalayk alqurān litašqē 3) ʔillā taðkirah liman yaxšē 4) tanzīlā mimman xalaq ʔalarɮˤ walsamāwāt alʕulē 5) alraħmān ʕalay ʔalʕarš ʔastawē 6) lah mā fī lsamāwāt wamā fī larɮˤ wamā beynahumā wamā taħt alṯarē 7) waïn taɟhar bilqawl faïnnah yaʕlam ʔalsirr waäxfē 8) ʔallāh lā ʔilāh ʔillā huww lah alasmāʔ ʔalḥusnē 9) wahal ʔatēk ħadīθ mūsē 10) ið rāä nārā faqāl liählih amkuθū ʔinnī ʔānast nārā laʕallī ātīkum minhā biqabas aw aɟid ʕalay alnār hudē 11) falammā atēhā nūdī yāmūsē 12) innī anā rabbuk faäxlaʕ naʕleyk innak bilwād almuqaddas ṭuwē 1) ṭāhā 2) mā ʔanzalnā ʕaleyka lqurʔāna litašqā 3) ʔillā taðkiratan liman yaxšā 4) tanzīlan mimman xalaqa lʾardˤa wassamāwāti lʕulā 5) ʾarraħmānu ʕalā lʕarši stawā 6) lahū mā fī ssamāwāti wamā fī lʾarḍˤi wamā beynahumā wamā taħta θarā 7) waʾin tajhar bilqawli faʔinnahū yaʕlamu ssirra waʔaxfā 8) ʾʔallāhu lā ʔilāha ʔillā huwa lahū lʔasmāʾu lḥusnā 9) wahal ʾatāka ḥadīθu mūsā 10) ʾið raʔā nāran faqāla liʔahlih imkuθū ʔinnī ʔānastu nāran laʕallī ʔātīkum minhā biqabasin ʔaw ʔajidu ʔalā nnāri hudā 11) falammā ʔatāhā nūdiya yāmūsā 12) ʾinnī ʔana rabbuka faxlaʕ naʕleyka ʾinnaka bilwādi lmuqaddasi ṭuwā Notes: Proto-Arabic nouns could take one of the five above declensions in their basic, unbound form.
The QCT along with the papyri of the first century after the Islamic conquests attest a form with an l-element between the demonstrative base and the distal particle, producing from the original proximal set ḏālika and tilka.
The Damascus Psalm Fragment in Greek script represents a later form of prestige spoken dialect in the Umayyad Empire that may have roots in Old Hejazi.