Definition of the Oneness of Allah’s Lordship
The linguistic meaning of the word Ar-Rabb (Lord)
Al-Baydaawi said, “The Arabic word Ar-Rabb is a verbal noun that means nurturing, which indicates something is progressing until it gradually reaches the point of perfection. It is used with reference to the Owner, because ownership entails that he is looking after and nurturing that which he owns.” [35] Tafseer al-Baydaawi, 1/28.
- The meaning of the word Ar-Rabb when used to refer to Allah, the Exalted.
Ibn Jareer said, “Our Lord, Exalted be His Praise, is the Master that nothing is likened to Him, and He is unparalleled in His sovereignty. He upholds the affairs of His creation through the abundant blessings that He bestowed upon them. He is the Owner in Whose Hands is the creation and the command.” [36] Tafseer Ibn Jareer, 1/143.
Ibn al-Qayyim said, “Ar-Rabb is the Master, the Owner, the Benefactor, the Nurturer, and the Upholder. Given all these considerations, Allah, Exalted be He, is the Rabb.” [37] Badaai’ al-Fawaaid, 4/132.
The word Ar-Rabb may not be used for any created being except in a possessive form, such like ‘Rabb ad-Daar’ (the lord of the house) and ‘Rabb al-Maal (the owner of wealth).
Ibn Qutaybah said, “It is not permissible to say regarding a created being: “This is the Rabb, while using the definitive article alif and laam as is said with regards to Allah. To use it for a created being, the possessive form should be used – that is to say, “The Rabb of such-and-such.” This is because Allah is the Owner of everything, and when it is said, “Ar-Rabb” the definite article (i.e. alif and laam) are indicative of a general meaning. However, when “Rabb” is used with regards to the creation it is said: “Rabb of such and such a thing,” it is attributed to a specific object because the person possesses that thing alone.” [38] Ghareeb al-Quran, p 9.
Some scholars explained that the word Ar-Rabb is not used for other than Allah if it is not used in a possessive form or in a defined manner. Ibn Al-Atheer said, “The word Ar-Rabb is not used in a non-possessive form except with regards to Allah, but when used for anything else, it is used in a possessive form; thus, it is said: “The Rabb of such-and-such.” [39] An-Nihaayah fee Ghareeb al-Hadeeth, 2/179.

Definition of the Oneness of Lordship in Islam:
The Monotheism of Lordship is the definitive affirmation of Allah’s Lordship (Exalted be He), over everything, and that He is their King, Creator, Controller, and the One who controls its affairs, He has no partner in His dominion, and He has no contender in any matter of His Lordship. [40] Minhaaj as-Sunnah an-Nabawiyyah by Ibn Taymiyyah, 3/289, Tatheer al-‘Itiqaad by as-San’aani, p 56, Taaj al-‘Aroos by az-Zubaydi, 9/276, Ma’aarij al-Qabool, 1/99, A’laam as-Sunnah al-Manshoorah li I’tiqaad at-Taaifah an-Naajiyah al-Mansoorah, p 33.
Ibn al-Qayyim said, “(The one who affirms the monotheism of Lordship) witnesses the self-subsistence of Allah above His throne, He alone controls the affairs of His servants. There is no creator, upholder, giver nor withholder, giver of life nor causer of death, no controller of the kingdom externally and internally except Him. Whatever He wills happens, and what He does not will, does not. Not a single atom moves except with His permission, and nothing happens except by His permission. No leaf falls except with His knowledge (of it), nothing in the heavens and earth is hidden from Him nor escapes his knowledge, even down to the smallest atom. His omnipotence encompasses all and His will puts it in effect, and His wisdom necessitates it. This is the summation of the monotheism of Lordship.” [41] Madaarij as-Saalikeen, 3/471.

Significance of the Monotheism of Lordship:
Monotheism of Allah’s Lordship involves acknowledging Allah’s greatness, and that He is the Only Creator, Owner, and Controller.
Allah, the Exalted, said, "Say (O Muhammad), "Who (else then) provides for you from the heaven and the earth? Or who owns hearing and sight? And who brings forth the living from the dead and the dead from the living? And who governs every matter?" They will say, ‘Allah.’ Say, ‘Will you not then be afraid of Allah's Punishment (for setting up rivals in worship with Allah)?” Such is Allah, your Lord in truth. So, after the truth, what else can there be, save error? How then are you turned away." (Yoonus: 31-32)
‘Abdullah ibn Mas’ood (may Allah be pleased with him) narrated, “I asked the Prophet (صلى الله عليه وسلم) "Which sin is the greatest in the Sight of Allah?" He said, "That you set up a rival unto Allah though He Alone created you.” [42] Transmitted by al-Bukhaaree (4477) and Muslim (86).
Monotheism of Allah’s Lordship leads to accepting monotheism of Worship, that is, singling out Allah alone in worship, associating none with Him.
Allah, the Exalted, said, "O mankind, worship your Lord, who created you and those before you, that you may become righteous. He who made for you the earth a bed spread out and the sky a ceiling and sent down from the sky, rain, and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know (that there is nothing similar to Him)." (al-Baqarah: 21-22)
In the explanation of this noble ayah, Ibn Katheer said, “Allah, Exalted be He, begins to explain the Oneness of His Worship by stating that He is the bestower of favours upon His servants, by taking them out of non-existence to existence, and abundantly providing them with blessings, both hidden and apparent. This means that Allah is the Creator, the Upholder, the Owner of the worldly abode and its dwellers, and their Nourisher. Therefore, Allah alone deserves to be worshipped and no partners should be associated with Him. Thus, He said: So do not attribute to Allah equals while you know that there is nothing similar to Him.” [43] Tafseer Ibn Katheer, 1/194.
Ibn al-Qayyim said, “The first thing that the heart is attached to is the monotheism of Lordship, then it elevates to embrace the monotheism of Worship. Allah in His Book calls His servants from one form of monotheism to another, and He uses that as proof against them, and makes them affirm it. Then, He informs them that they oppose it when they set up partners in worship.” [44] Madaarij as-Saalikeen, 1/412, Majmoo’ al-Fataawa by Ibn Taymiyyah, 10/284, Sharh at-Tahhaawiyyah by Ibn Aboo al-‘Izz, 1/36, Madkhal li Diraasat al-‘Aqeedah al-Islaamiyyah by ‘Uthmaan Dumayriyyah, p 223, Manhaj Ahl as-Sunnah wa al-Jamaa’ah wa manhaj al-Ashaa’irah fee Tawheedillah Ta’aala by Khaalid ‘Abd al-Lateef, 1/242.