What is the ruling on money earned from private work that was carried out using the equipment of the institution where the person works, without its knowledge, given that the institution violated the contract initially agreed upon? Is it obligatory to give out only the amount equivalent to the cost of renting the equipment, or is the entire amount unlawful? And what is the situation regarding their violation of the initial contract, especially with subsequent salary increases?

The questioner must return the injustices to their rightful owners or seek their forgiveness for them. He can either inform the company owners about what truly happened, or return their right to them—the value of the rent for the devices used in his private work—without their knowledge. Even if the consequences of their breach of the first contract were clear injustice that entitled him to rights, he agreed to the new contract, thereby waiving his right. Therefore, he has no right with them except what was recently agreed upon, and he must fulfill their right regardless of their injustice.