A king entrusted a tutor with the care of his son, saying: ‘This is your son. Educate him as if he were one of your own children.’ He kept the prince for some years and strove to instruct him but could effect nothing, whilst the sons of the tutor made the greatest progress in accomplishments and eloquence. The king reproved and threatened the learned man with punishment, telling him that he had acted contrary to his promise and had been unfaithful. He replied: ‘O king, the instruction is the same but the natures are different.’
Although both silver and gold come from stones
All stones do not contain silver and gold.
Canopus is shining upon the whole world
But produces in some places sack-leather and in others adim.
When a nature is originally receptive
Instruction will take effect thereon.
No kind of polishing will improve iron
Whose essence is originally bad.
Wash a dog in the seven oceans,
He will be only dirtier when he gets wet.
If the donkey of Jesus be taken to Mekkah
He will on his return still be a donkey.
Source: The Gulistan of Sa’adi
Some people are blessed with a receptive nature, others are able to achieve it with sincere intentions, efforts and prayers.