Swami Rama (Living with the Himalayan Masters) once visited a Swami in the Himalayas and they were discussing the Brahma Sutras which are among the most difficult Vedantic scriptures. Swami narrated this story to stress the importance of direct knowledge.
There was a guru, he had a disciple. The disciple had never seen a cow nor had he tasted the milk, he had read that the cow milk is very nutrient and was very curious to find a cow and taste its milk. He approached his guru and asked “Do you know anything about the cows?”
“Yes.” replies the Master.
“Then would you please explain what a cow looks like?” the disciple prayed.
The Guru explained: “A cow has four legs, It does not live in the forest. it’s a domestic animal,you can find one in the villages, It gives white milk which is good for health.” The Master gave him a lot more information on the features of a cow: the eyes, ears, legs, stomach, udder, horns.
The Student went to a village and there he saw a statue of the cow, someone was painting an adjacent compound wall with chalk had left a bucket full of lime water near the statue of the cow.
The student saw the cow and observed its features, he finally came to the conclusion that it must be the cow, he also saw a bucket with white liquid near by. ‘This is definitely a cow, so this must be the milk’ thought the disciple and drank some of it. He soon started screaming with pain, he had to be hospitalized.
His Guru visited him in the hospital, “What happened?” the Guru asked.
“Master you don’t know anything about the cows or the milk, you are totally wrong.” the disciple answered.
“Tell me what happened.” The Guru sought an explanation. The student explained everything.
“Did you milk the cow yourself?” asked the Guru.
“That’s why you are in trouble. Until you rely on what others say you won’t get to the truth which will liberate you.” The Wise Guru replied.
Story: In Buddhism