Sunan at-Tirmithiy كتاب صفة جهنم

حَدَّثَنَا سَلَمَةُ بْنُ شَبِيبٍ حَدَّثَنَا عَبْدُ الرَّزَّاقِ أَخْبَرَنَا مَعْمَرٌ عَنْ زَيْدِ بْنِ أَسْلَمَ عَنْ عَطَاءِ بْنِ يَسَارٍ عَنْ أَبِى سَعِيدٍ الْخُدْرِىِّ أَنَّ النَّبِىَّ صلى الله عليه وسلم قَالَ يُخْرَجُ مِنَ النَّارِ مَنْ كَانَ فِى قَلْبِهِ مِثْقَالُ ذَرَّةٍ مِنَ الإِيمَانِ. قَالَ أَبُو سَعِيدٍ فَمَنْ شَكَّ فَلْيَقْرَأ إِنَّ الله لاَ يَظْلِمُ مِثْقَالَ ذَرَّةٍ. قَالَ هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ.
The Messenger of God, peace and blessings of God be upon him, said, “Those with an atom’s (1) weight of faith in their hearts will be removed from the Fire.” The narrator added, “Whoever doubts this should read, ‘Indeed, Allah does not do injustice, [even] as much as an atom's weight’ (4 [An-Nisā']: 40).” 1) The word “atom” in Qu’rān and hadīth refers to minute particles in general. However, it does not refer to the word “atom” known nowadays in the science of Chemistry. This is because the new meaning of “atom” in Chemistry was added to the same Arabic word “tharrah” only in modern times (around the beginning of the 20th century). However, in classical Arabic texts, it is said that an atom can be equivalent to particles as small as motes that appear suspended in a beam of sunlight, a small ant, or particles that fall from the hand while shaking off dust. Click on ḥadīth to read more