What is the Sharia ruling on taking sick leave without need, or being absent from classes with the teacher's permission but without the administration's knowledge, while the teacher records the student as present when they are absent?

It is not permissible for a student to seek a sick leave unless he is actually sick and in need of it.

It is not permissible for an unauthorized person to grant absent students permission to attend, as this constitutes deception, betrayal, and falsehood.

There is no objection to the company's management allowing some students to be absent without deducting from their salaries, if they are authorized to do so by the company owner, or if such absence is deducted from the total permitted hours.

As for deducting double the value of the total absence hours from the salary: If the salary is a grant from the company, then there is no objection to that, because the company is free in its grants. However, if the salary is in exchange for the students' attendance based on a contract, then it is not permissible to deduct double the value of the absence. Rather, it is only permissible to deduct the wages for the hours they were absent. The company may discipline them administratively.

Students must abide by contracts, as Allah Almighty says: "O you who have believed, fulfill [all] contracts," and the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions in what is lawful."