The Crab and Its Mother
The mother crab did not like her young one walking sideways on the beach continuously and scolded him. The mother said "My child, why do you walk so crookedly and sideways? Why don't you learn to walk properly and straight ahead?" The young crab looked at his mother and answered "Well mommy, first you walk straight in front of me so I can watch you and learn." When the mother crab tried it herself, seeing that she could not walk any other way than sideways, she felt embarrassed.
It is hypocrisy for those who cannot behave correctly themselves to attempt to teach others to behave correctly. The person giving advice should first correct their own behavior and lead by example by living what they say. Those who do not see their own flaws and criticize others face their own inadequacies in the first test. Setting an example is possible not through fancy words, but through correct and proper actions.
Walk straight yourself first so you can be an example to others. Setting an example is not done with words. One who does not see their own flaw cannot give advice. Word without action is invalid.
First correct your own path. Do not ask from another what you cannot do. Living correctly is the greatest advice.