Sibghatullah
It comes from Surah Al-Baqarah (2:138): 'Take on the coloring (sibghah) of Allah; and who is better than Allah at coloring?'
It refers to the fitrah—the innate monotheistic nature Allah instills in every human, colored by the pure religion of Islam.
Yes, it appears in Ottoman scholarly records and among Abbasid jurists, though it has always been rare.
While traditionally kept in full form, Sibgha is occasionally used as a shortened version, though this loses the theophoric element.
Traditionally masculine, though the abstract concept of sibghah is gender-neutral in Arabic grammar.