Failure instructs, failure improves. Failure shouldn't deter you.
Every religion is good that teaches man to be good; and I know of none that instructs him to be bad.
The proverbial wisdom of the populace in the street, on the roads, and in the markets instructs the ear of him who studies man more fully than a thousand rules ostentatiously displayed.
Hereditary sloth instructs me.
To do something right it must be done twice. The first time instructs the second.
I hate everything that merely instructs me without augmenting or directly invigorating my activity.
He who honestly instructs reverences God.
Prayer purifies us, reading instructs us. Both are good when both are possible. Otherwise, prayer is better than reading.
The Lord instructs me not to judge any man.
Just as a person is commanded to honor and revere his father, so he is under an obligation to honor and revere his teacher, even to a greater extent than his father; for his father gave him life in this world, while his teacher instructs him in wisdom, secures for him life in the world to come.
That which hurts, also instructs.