Luke 22:29

“And I appoint to you (covenant to you) a kingly rule, even as my Father appointed (covenanted) to me,”

And because they had continued faithfully with Him, walking in His way, and accepting His standards, He was now appointing to them a kingly rule even as His Father had appointed one to Him. He was making them His deputies. They would now take over responsibility for the Kingly Rule of God on earth, and it was because they had developed servant hearts. Note the connection of the word with covenant. This was binding between Him and them.

But as we have just been told, this was not to be the normal kind of kingly rule. For when He had drawn men under the Kingly Rule of God, what Had He then done? He had exercised His kingly rule over them in humility and as a Servant. He had had no thought of lording it over them, but of being their servants for His Father's sake. He had given Himself to the point of exhaustion. And now they must do the same for His sake. For God's Kingly Rule was over all who belonged to God, over all who were submitted to, or willing to submit to Him. And like He Himself had been, they themselves were in the same way to be servant-rulers under God in the expanding of His Kingly Rule and for the glorifying of His Name. They were to tend and feed the sheep (John 21:15). They were to give themselves for the sheep.