Is the gift presented to the manager after the bid is awarded to the party that offered the lowest price considered permissible or impermissible?

Gifts given to employees are forbidden by Islamic law, even if given after the work, if the work was the reason for them, unless the employer permits it. This is to prevent pretexts, for the Prophet, peace and blessings be upon him, said: "Gifts to employees are ill-gotten gains (ghulul)." This is also based on his story with Ibn al-Lutbiyyah when he said to him: "Why don't you sit in your father's and mother's house, until your gift comes to you, if you are truthful?"