What is the ruling on the Imam's saying to the congregants when lining up for prayer: "Pray the prayer of one bidding farewell"?

It is stated in the Hadith (definition) that the Prophet, peace and blessings be upon him, said: "When you stand for your prayer, pray the prayer of one bidding farewell." The intention behind this is for the worshipper to feel that this is their last prayer, so they perform it with humility, tranquility, and perfection. This statement should not be taken as a constant rule, but rather as an admonition at times, because what is firmly established from the Prophet, peace and blessings be upon him, is the command to straighten the rows and stand shoulder to shoulder.