What is the ruling on giving money to nurses in a hospital in exchange for a service or information, knowing that they receive a salary? And what is the ruling on giving money to the reservation clerk at the train station in exchange for booking an unavailable ticket, and is this considered bribery? And is it obligatory to say "Allah knows best" when issuing a fatwa or informing someone with knowledge?

What the nurse takes from patients and visitors in exchange for his work is considered ill-gotten gain (suḥt), and paying an amount to a travel station employee for booking is a prohibited bribe (rishwah), as it leads to prioritizing the payer over others. If the person requesting the booking has a right and is unjustly denied it, and cannot obtain it except by paying money, then there is no sin upon him, and the sin falls upon the employee who takes it. Saying "Allah knows best" after conveying a fatwa or a scholarly issue is not obligatory, but it is good as a matter of etiquette and attributing knowledge back to Allah.