Hadith: That is a word pertaining to the truth which a jinn snatches and whispers into his friend's ears as a hen does. Then, they mix it with more than a hundred lies

عن عائشة رضي الله عنها قالت:
سَأَلَ أُنَاسٌ رَسُولَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ عَنِ الْكُهَّانِ، فَقَالَ لَهُمْ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «لَيْسُوا بِشَيْءٍ» قَالُوا: يَا رَسُولَ اللهِ، فَإِنَّهُمْ يُحَدِّثُونَ أَحْيَانًا بِالشَّيْءِ يَكُونُ حَقًّا، فَقَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «تِلْكَ الْكَلِمَةُ مِنَ الْحَقِّ يَخْطَفُهَا الْجِنِّيُّ فَيَقُرُّهَا فِي أُذُنِ وَلِيِّهِ قَرَّ الدَّجَاجَةِ، فَيَخْلِطُونَ فِيهَا أَكْثَرَ مِنْ مِائَةِ كَذْبَةٍ».
[صحيح] - [متفق عليه] - [صحيح البخاري: 6213]

‘Ā’ishah (may Allah be pleased with her) reported:
Some people asked the Messenger of Allah (may Allah's peace and blessings be upon him) about diviners, and he said to them: "They are of no account." They said: "O Messenger of Allah, but they sometimes make true predictions." Thereupon, the Messenger of Allah (may Allah's peace and blessings be upon him) said: "That is a word pertaining to the truth which a jinn snatches and whispers into his friend's ears as a hen does. Then, they mix it with more than a hundred lies."
[Authentic hadith] - [Narrated by Bukhari & Muslim] - [Sahih Bukhari - 6213]

Explanation

The Prophet (may Allah's peace and blessings be upon him) was asked about those who speak about unseen and future things, and he said: Pay no attention to them and do not believe them.
They said: Their statements sometimes conform with reality - they say that something will occur in such and such month on such and such day, it actually happens as they stated.
Thereupon, the Prophet (may Allah's peace and blessings be upon him) said: The jinn snatch what they hear from the heavenly information, descend upon their allies from among the diviners, and convey what they heard to them. Then, the diviners add a hundred lies to this piece of information that reached them from heaven.