Does an employer bear the burden of his employee's mistakes in buying and selling, despite having warned him to seek what is lawful?

If you choose an employee who is proficient and knowledgeable in their work, you bear no sin for their error or transgression, as long as you were unaware of it and did not approve of it. Allah Almighty says: "And no bearer of burdens will bear the burden of another." You should encourage your workers to be precise and avoid errors. If you receive money due to an error and become aware of it, you are obligated to return it.