In the name of Allah the Most Beneficent the Most Merciful,
ضَرَبَ لَكُم مَّثَلًا مِنْ أَنفُسِكُمْ هَل لَّكُم مِّن مَّا مَلَكَتْ أَيْمَانُكُم مِّن شُرَكَاء فِي مَا رَزَقْنَاكُمْ فَأَنتُمْ فِيهِ سَوَاء تَخَافُونَهُمْ كَخِيفَتِكُمْ أَنفُسَكُمْ كَذَلِكَ نُفَصِّلُ الْآيَاتِ لِقَوْمٍ يَعْقِلُونَ
“He presents to you an example from yourselves. Do you have among those whom your right hands possess any partners in what We have provided for you so that you are equal therein [and] would fear them as your fear of one another [within a partnership]? Thus do We detail the verses for a people who use reason.”
In the verse we are discussing in this post God does not refer to the humans in bondage as slaves but rather as what your right hands possess.This is because in the Islamic context only God is the true Lord who owns all humans.He is the only One we obey without question because at then end of the day He is our Perfect Lord so we are His slaves and proud to be His slaves.Constantly through the Quran Allah refers to Himself as Master/Lord and us humans as slaves.He who ponders on this will realize that we are all slaves to something or someone but the only true Lord is Allah.
Human owners did not see it befitting to make their slave owners partners in wealth.Why?Perhaps they thought they owned them(which in reality they never did) or perhaps they thought their slaves were of a lower class than them.Whatever the case they did not find it appropriate to make them partners in their wealth such that they were equals.
Now these same people used to claim that God has partners.If they felt it beneath themselves to share property rights with their slaves how could they then make such a claim about God?Why would God give part of His sovereignty to that which He owns in the complete and absolute sense?
If humans had the characteristic of being unwilling to share their ownership with those they thought they owned it is less befitting for Allah to take partners.In addition to that Allah says it is He who provides.Thus that which they are unwilling to be co-equals with their slaves in is in actual fact not originally their but a provision from God Himself.
Everything that exists other than Allah was at one point non-existent.Thereafter Allah willed that it should come to be.Hence He owns all of it.The entire universe and all that is in it belongs to Allah.He is the True King and thus He is in no need of taking partners.
Allah has detailed the signs for a people who reason.Allah our Lord is One.He has no partners,spouses,offspring or the like.He is One in His Lordship,Godhead and His Perfect attributes.There is no god other than Allah,who in His Oneness has no partners,to Him belongs absolute dominion and praise and He is over all things competent.
…and Allah knows best.
Asalaam aleykum warahmatullahi wabarakatuh. (May the peace and Mercy and Blessings of Allah be upon you.)