Mosiah 27:21 - 27:25

Mosiah 27:21 And he caused that a multitude should be gathered together that they might witness what the Lord had done for his son, and also for those that were with him.

Alma Sr. then had gather a group of people to see the condition of his son after the manifestation of the angel and the witness of the others who were with him.

Mosiah 27:22 And he caused that the priests should assemble themselves together; and they began to fast, and to pray to the Lord their God that he would open the mouth of Alma, that he might speak, and also that his limbs might receive their strength—that the eyes of the people might be opened to see and know of the goodness and glory of God.

The priests and others now prayed and fasted for Alma Jr. that he would be able to move and speak. Alma Sr. was anxious for the people to see the effect of the visit of the angel had on his son.

Mosiah 27:23 And it came to pass after they had fasted and prayed for the space of two days and two nights, the limbs of Alma received their strength, and he stood up and began to speak unto them, bidding them to be of good comfort:

They prayed and fasted for two days for Alma Jr’s recovery. When Alma did recover his strength, he calmed the anxiety of the people by telling them that he was alright.
[Wonder why it was necessary to fast for Alma. Why did they just wait for his recovery? It may be that Alma Sr. was trying to get the people’s minds focused on what Alma Jr. would be saying when he came out of his coma. Alma Sr. surely expected to hear things that would require the people to be in a spiritual mind set to really understand and feel for themselves.]

Mosiah 27:24 For, said he, I have repented of my sins, and have been redeemed of the Lord; behold I am born of the Spirit.

Alma tells the people that he has repented of his sins and knows what it is like to be saved from his sins.

Mosiah 27:25 And the Lord said unto me: Marvel not that all mankind, yea, men and women, all nations, kindreds, tongues and people, must be born again; yea, born of God, changed from their carnal and fallen state, to a state of righteousness, being redeemed of God, becoming his sons and daughters;

The Lord spoke to Alma Jr. in his comatose state telling him that all mankind had to be born of the spirit. That they had to change their desire for mortal things and have a desire for spiritual things. They needed to be oriented toward things which helped people to become more like God so they could be sons and daughters of God. Sons and daughters in the sense they were wanted to do as He does.
[A follower is one who wants to live just like their master who they look up to for guidance and direction in life. Student might be a better way to put this, but son or daughter indicates a closer relationship than just teacher—student association.]