Ar-Rashid does not appear as a standalone divine name in an authentic hadith with a strong chain, nor as this exact noun applied to Allah in the Qur’an. It is widely printed in popular lists of the 99 (via the Tirmidhi enumeration), and its meaning — the One who guides every affair to its right and wise conclusion — is solidly supported by the Qur’an’s many verses on Allah’s guidance (huda), even though this precise wording is not found describing Him directly in an ayah.
Ar-Rashid guides all affairs to their proper, wise conclusion, though this exact wording is less firmly attested in the Qur'an or hadith than most other names on this list.