It is against his own soul

We certainly gave Moses the Book aforetime: but disputes arose therein. Had it not been for a Word that went forth before from thy Lord, (their differences) would have been settled between them: but they remained in suspicious disquieting doubt thereon. {45} Whoever works righteousness benefits his own soul; whoever works evil, it is against his own soul: nor is thy Lord ever unjust (in the least) to His Servants. {46} To Him is referred the Knowledge of the Hour (of Judgment: He knows all): No date-fruit comes out of its sheath, nor does a female conceive (within her womb) nor bring forth the Day that (Allah) will propound to them the (question), "Where are the partners (ye attributed to Me?" They will say, "We do assure thee not one of us can bear witness!" {47} The (deities) they used to invoke aforetime will leave them in the lurch, and they will perceive that they have no way of escape. {48} Man does not weary of asking for good (things), but if ill touches him, he gives up all hope (and) is lost in despair. {49} When we give him a taste of some Mercy from Ourselves, after some adversity has touched him, he is sure to say, "This is due to my (merit): I think not that the Hour (of Judgment) will (ever) be established; but if I am brought back to my Lord, I have (much) good (stored) in His sight!" But We will show the Unbelievers the truth of all that they did, and We shall give them the taste of a severe Penalty. {50} When We bestow favours on man, he turns away, and gets himself remote on his side (instead of coming to Us); and when evil seizes him, (he comes) full of prolonged prayer! {51} Say: "See ye if the (Revelation) is (really) from Allah, and yet do ye reject it? Who is more astray than one who is in a schism far (from any purpose)?" {52} Soon will We show them our Signs in the (furthest) regions (of the earth), and in their own souls, until it becomes manifest to them that this is the Truth. Is it not enough that thy Lord doth witness all things? {53} Ah indeed! Are they in doubt concerning the Meeting with their Lord? Ah indeed! It is He that doth encompass all things! {54}

(Surah Fussilat)