If a person commits a sin, and if he is punished for that sin in this world, then Allah Ta'ala will not punish him again for that sin in the Hereafter.
It was narrated that 'Ubadah bin As-Samit (Ra.) said: While there was a group of his companions around him, the Messenger of Allah said: "Pledge to me, that you will not associate anything with Allah, nor steal, nor commit unlawful sexual relations, nor kill your children; you will not utter slander, fabricating from between your hands and feet, and you will not disobey me in goodness (Ma'ruf). Whoever fulfills (this pledge), his reward will be with Allah, and whoever commits any of these actions and is punished for it, will be an expiation for him. Whoever commits any of these actions then Allah conceals him, then his affair is up to Allah; if He wills He will forgive him, and if He will punish him."
[Sunan An-Nasa'i, Hadith No. 4161]
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أَنَّ عُبَادَةَ بْنَ الصَّامِتِ قَالَ: إِنَّ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ وَحَوْلَهُ عِصَابَةٌ مِنْ أَصْحَابِهِ: «تُبَايِعُونِي عَلَى أَنْ لَا تُشْرِكُوا بِاللَّهِ شَيْئًا، وَلَا تَسْرِقُوا، وَلَا تَزْنُوا، وَلَا تَقْتُلُوا أَوْلَادَكُمْ، وَلَا تَأْتُوا بِبُهْتَانٍ تَفْتَرُونَهُ بَيْنَ أَيْدِيكُمْ وَأَرْجُلِكُمْ، وَلَا تَعْصُونِي فِي مَعْرُوفٍ، فَمَنْ وَفَّى فَأَجْرُهُ عَلَى اللَّهِ، وَمَنْ أَصَابَ مِنْكُمْ شَيْئًا فَعُوقِبَ بِهِ، فَهُوَ لَهُ كَفَّارَةٌ، وَمَنْ أَصَابَ مِنْ ذَلِكَ شَيْئًا، ثُمَّ سَتَرَهُ اللَّهُ فَأَمْرُهُ إِلَى اللَّهِ، إِنْ شَاءَ عَفَا عَنْهُ، وَإِنْ شَاءَ عَاقَبَهُ»
[سنن النسائى ، رقم الحديث ٤١٦١]