Mainly Quran has revealed to receive admonition in it.
كِتَابٌ أَنزَلْنَاهُ إِلَيْكَ مُبَارَكٌ لِيَدَّبَّرُوا آيَاتِهِ وَلِيَتَذَكَّرَ أُوْلُوا الأَلْبَاب
(Here is) a Book which We have sent down unto thee full of blessings that they may meditate on its Signs and that men of understanding may receive admonition. (38:29)
Arabic Word Albab is plural of Lub: Lub means most clarified part of something
like the essence of something.
actual seed the kernel inside after you remove the skin and shaft then what you have inside called the lub.
Here means it's pure from lust and brain should work in right direction and think in proper manners which is free from desires and justifications.
The ability for you is not be influence by the bad and the corrupt regardless that to be influenced by the good and pure and then convey from the good and abstain to conveying from evil this is also one of the aspects of lub.
In science all are from brain but Allah talks always about heart because this is the source of all organs in one aspect.