First attestation of the Arabic name for the Lord's Prayer الصلاة الربية/ الربانية

[Motaz AL-THAHER]

Dear colleagues,

My name is Motaz Al-Thaher. I am a Visiting Researcher at the Centre for Muslim-Christian Studies (CMCS), and I have recently joined this group. https://www.cmcsoxford.org.uk/motazal-thaher

Does anyone know the earliest attestation of the Arabic designation for the Lord's Prayer (e.g., al-Ṣalāh al-Rabbiyya, al-Ṣalāh al-Rabbāniyya, الصلاة الربية, الصلاة الربانية) . I am particularly interested in identifying the earliest extant Arabic source that uses one of these two terms.

Thanks