Is delivering the Friday sermon on behalf of imams and خطباء (preachers) appointed by the Ministry of Endowments considered assisting them in neglecting their official duty and being lazy about it, or is it a permissible act with no objection to it?

Conditions must be fulfilled in contracts, for the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions, except for a condition that forbids what is lawful or permits what is unlawful." And for His, the Almighty's, saying: "O you who have believed, fulfill [your] contracts." Therefore, it is not permissible for Friday preachers to substitute someone to preach in their place except with explicit or implicit permission from their employer (the Ministry of Endowments).