Hadith: That is the clear Imān (faith)

عَنْ أَبِي هُرَيْرَةَ، قَالَ: جَاءَ نَاسٌ مِنْ أَصْحَابِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ، فَسَأَلُوهُ: إِنَّا نَجِدُ فِي أَنْفُسِنَا مَا يَتَعَاظَمُ أَحَدُنَا أَنْ يَتَكَلَّمَ بِهِ، قَالَ: «وَقَدْ وَجَدْتُمُوهُ؟» قَالُوا: نَعَمْ، قَالَ: «ذَاكَ صَرِيحُ الْإِيمَانِ»
[صحيح] - [رواه مسلم]

Abu Hurayrah (may Allah be pleased with him) reported: Some of the Prophet's Companions came to him and said: "We find within ourselves thoughts that one of us would find too grave to talk about." He said: "Have you experienced that?" They said: 'Yes'. He said: "That is the clear faith."
Sahih/Authentic. - [Muslim]

Explanation

Abu Hurayrah (may Allah be pleased with him) reported that a group of the Prophet's Companions came to him and said: We find in ourselves reprehensible thoughts - like Who created Allah? How is He? What is He made of? - that we find too grave to give utterance to because we know that this is so bad and inappropriate to think about. So, what is the ruling regarding having such thoughts? In response, the Prophet (may Allah’s peace and blessings be upon him) asked: Did this happen? Did you experience that? They replied in the affirmative. Thereupon, he said: That is the clear Imān (faith), which means: It is the clear faith that prevents you from accepting and believing the whisperings Satan puts into your minds, and thus they cannot take hold in your hearts and souls. In other words, your view of this as being too grave and your fear from uttering it is the clear faith. The phrase does not mean, however, that the whispering itself is the clear faith, as it comes from Satan and his temptations and it happens with atheists and disbelievers; so, how could it be a clear faith!