Ar-Ra'd 13:4

‘Abdullah ibn ‘Abbas says that one strip of land is fertile while another is barren. One strip of land produces crops while one nearby does not. Mujahid says that the same is the case with mankind. There are good people in this world and also bad, though the origin of all is one. There is a strange phenomenon on this earth: the soil in different places may be similar and may be watered by the same water, but in one place it will produce a tree whose fruit is sweet, while in another place it will produce a tree whose fruit is sour. One tree may have a high yield and another a low yield. This is a parallel in nature to the human condition. It is like all human beings, although cast in the same mould, showing a marked difference from one individual to another when it comes to deriving any benefit from the divine guidance which is consistently offered to all. One will receive the full benefit of such guidance, and thus have his entire life enriched by it, while another may avail of only a part of it or even reject it altogether. In other words, the same ‘seeds’ of guidance when ‘sown’ in different individuals will produce outcomes as different as the sweet and sour fruits of our analogy.