Is it permissible for an employee to buy goods and sell them to the institution he works for, benefiting from the authority of his manager who gives him purchase orders for office supplies or cleaning materials, even though the law requires submitting the purchase order to several suppliers and choosing from among them?

The scenario in question involves several Shariah prohibitions that prevent its permissibility, namely:

1. The manager's failure to adhere to work conditions and regulations, and favoritism towards the questioner at the expense of the company's interest. This is considered a betrayal of the company, and it is not permissible to cooperate with him in this.

2. Creating fictitious invoices is a form of forbidden lying and deception, and it is not permissible to give money in exchange for a commercial register.

3. It is not permissible for a private employee to work for his own personal benefit during working hours, because his time belongs to the employer, unless with their permission or what has been exempted by Shariah or custom.