Do not be too hard, lest you be broken; do not be too soft, lest you be squeezed.
Ali Ibn Abi Talib
Do not share the knowledge with which you have been blessed with everyone in general, as you do with some people in particular; and know that there are some men in whom Allah, may He be glorified, has placed hidden secrets, which they are forbidden to reveal.
He who busies himself with things other than improvement of his own self becomes perplexed in darkness and entangled in ruin. His evil spirits immerse him deep in vices and make his bad actions seem handsome.
Do for this life as if you live forever, do for the afterlife as if you die tomorrow.
A man's measure is his will.