Hadhrat Abu Sulaimaan Daaraaee (rahmatullah alayh) said:
Everything has its corrosion. Eating to the degree of satiation is the corrosion of the heart's purity. Ihtilaam (nocturnal discharge of semen) is a punishment for filling the stomach.
A man who eats his stomach full suffers six calamities:
1) He does not experience pleasure in Ibaadat.
2) His memory in remembering wisdom decreases.
3) He is unable to be affectionate to people.
4) Ibaadat is onerous on him.
5) His lust increases.
6) He is preoccupied with the toilet.
He said: A man in whose heart is noor (spiritual light) is angered by nafsaani desires. That noor separates him from the world and inclines him to the Aakhirah.
Abandonment of ego is called Tawaadhu' (humility). (As long as one thinks of oneself as being something, one lacks humility.) He who does not recognize his nafs does not understand the meaning of Tawaadhu'.
One who speaks without thinking always regrets.
Eating less, sleeping less and speaking less are the signs of a sincere taubah.
The Thikr of Allah effaces sins and His Ridhaa (being pleased with Him) severs vain hopes.
Extracted from: Scattered Pearls - Majlisul Ulama of South Africa