Linguistically the word Rabb means master, owner, one who grants grace, one who sets about correcting and purifying, and one who nurtures and cultivates. It is said that the latter meaning is the core meaning of the word and the other meanings stem from it. When used in a possessive or conjunctive structure it can be applied to other then Allah, for example it is said rabb ad-dar, or the master of the house, similarly in the Qur’an it is mentioned that Yusuf, peace be upon him, said to one of the inmates of prison, “Mention me in the presence of your master.” (Yusuf 12:42)
Likewise it is mentioned in the famous hadith of Jibril, when the Prophet, may Allah’s peace and blessings be upon him, listed some of the signs of the Hour, “…when the slave-girl gives birth to her master.” (Muslim 1)
However the word ar-Rabb can only ever be applied to Allah. (al-Qurtubi, vol 1, p96) It is one of the Names of Allah and means the One who nurtures and sustains all of His servants through regulating the affairs and granting all types of favours and blessings. More specifically he is the One who nurtures and sustains his sincere friends by correcting and purifying their hearts, souls and manners. This is why their supplications are frequently made with this Noble Name because they seek this specific nurturing.” (as-Sadi, p16)
As-Sadi said, ‘The Lord is One who nourishes and sustains the whole of the creation, meaning everything aside from Allah, by the very fact of His creating them, His preparing for them all that they need and His favouring them with great blessings which if removed would also remove any possibility of the creation surviving. Therefore every blessing they possess is from Him, Exalted is He.
His sustaining His creation is of two types: general and specific. As for the general, it is His creating the creation, granting them provisions and guiding them to that which would benefit them in order to have them survive in this world. As for the specific, it is His sustaining His friends with faith and making them conform to it, perfecting and completing it for them, repressing all that would make them turn away from it, bridling any hindering factors that may be set up between them and Him, and safe-guarding them from all evil. It is possible that the reason behind the fact that most of the supplications made by the Prophets employed the word, ‘Lord’ was due to it carrying this meaning, for indeed all of the things they desired through their supplications fell under His Specific Lordship.’ (as-sadi p22)
The Spiritual Cure: An Explanation of Surah Al-Fatihah prepared and translated by Abu Rumaysah Pages 80-82