Is it permissible for an employee to obtain a medical certificate while not ill, in order to get an essential leave to complete his marriage, knowing that he will not be paid for this period and will spend it in good deeds, given that he cannot obtain leave by any other means as he is at the beginning of his employment?

It is not permissible for an employee to fabricate false excuses for absence, nor for a doctor to forge certificates for him, because that is considered false testimony and one of the major sins. If an employee needs leave, he should explain his circumstances to the employers. Giving charity from the salary for the period of unlawful absence does not justify deception and the forging of certificates. A Muslim should only give charity from what is lawful.