Imam Baqir (peace be upon him): When Allah the Exalted brought forth the progeny of Adam from his back to take from them the covenant of His Lordship and the prophethood of every prophet, the first one for whom He took from them the covenant of prophethood was Muhammad ibn Abdullah (peace be upon him and his family). Then Allah said to Adam (peace be upon him): "Look, what do you see?" Adam (peace be upon him) looked at his progeny and saw them like tiny particles filling the sky. Adam (peace be upon him) said: "My Lord! How numerous my progeny is! And for what great matter have You created them, and what is Your purpose in taking the covenant from them?" Allah said: "They will worship Me and will not associate anything with Me (Nur/55), and they will believe in My messengers (peace be upon them) and follow them." Adam (peace be upon him) said: "My Lord! Why do I see some of the particles larger than others, and some of them have much light, and some of them have little light, and some of them have no light at all?" Allah the Blessed and Exalted said: "Thus I created them so that I may test them in all their states." Adam (peace be upon him) said: "My Lord! Do You permit me to say something?" Allah the Mighty and Majestic said: "Speak! Indeed your spirit is from My spirit, but your nature is contrary to the nature of My essence." Adam (peace be upon him) said: "My Lord! If You had created them upon one form and figure, and one size, and one nature, and one disposition, and identical colours, identical lifespans, and equal provisions, some of them would not have transgressed against others, and there would have been no envy or enmity among them, and they would not have disagreed with one another in any of the matters." Allah the Exalted said: "By the aid of My spirit you spoke, but because of the weakness of your nature you have said something you have no knowledge of. I am the Creator, the Knowing; by My own knowledge I made a difference in their creation, and by My will My command flows in them, and by My planning and decree they undergo change and transformation. There is no alteration in My creation. إِنَّمَا خَلَقْتُ الْجِنَّ وَ الْإِنْسَ لِیَعْبُدُونِ [Indeed I created the jinn and mankind only that they should worship Me], and I created Paradise for the one who worships Me and obeys Me and My messengers, and I pay no heed to anyone or anything. I created the Fire for the one who disbelieves in Me and disobeys Me and does not obey My messengers (peace be upon them), and I do not concern Myself with anything else. I created you and your progeny without any need of Mine for you or for them. I created you and your progeny only for this reason: to test them, to see which of you is best in deed in the abode of this world, in your lives and before your deaths. And likewise I created this world and the Hereafter, and life and death, and obedience and disobedience, and Paradise and Hell. Thus I willed in My decree and planning, and by My penetrating knowledge I distinguished between their faces and their bodies and their colours and their lifespans and their provisions and their acts of worship and their sins. So I made some of them fortunate and others wretched, some seeing and some blind, some short and others tall, some beautiful and others ugly, some knowing and others ignorant, some free of need and others in need, some obedient and others disobedient, some sound and healthy and others sick, some with bodily defects and others without any flaw or defect — so that the sound and healthy person may look upon the one who is afflicted with illness and praise Me for his health, and the one who has a defect or flaw may look upon the sound and healthy person and call upon Me and ask Me to grant him health and be patient with My trial, so that I may grant him My abundant bounty; and that the one free of need may look upon the needy and praise Me and give Me thanks; and that the needy may look upon the one free of need and call upon Me and ask of Me; and that the believer may look upon the disbeliever and praise Me for having guided him. Thus I created them, so that I may test them in ease and hardship, and in comfort and discomfort, and in what I grant them of health, and in what I try them with, and in what I bestow upon them, and in what I withhold from them. I am Allah, the Powerful and the Able, and it is upon Me to carry out with My planning all that I have decreed, and it is upon Me to change of that what I have willed, and to bring forward what I have placed later, and to delay what I have placed earlier. And I am the One Allah and I do what I will. I am not questioned about what I do, but I question My creation about their deeds."