John 21:21 WEB

¹⁹  Now he said this, signifying by what kind of death he would glorify God. When he had said this, he said to him, 'Follow me.'

²⁰  Then Peter, turning around, saw a disciple following. This was the disciple whom Jesus sincerely loved, the one who had also leaned on Jesus' breast at the supper and asked, 'Lord, who is going to betray You?'

²¹  Peter seeing him, said to Jesus, 'Lord, what about this man?'

²²  Jesus said to him, 'If I desire that he stay until I come, what is that to you? You follow me.'

²³  This saying therefore went out among the brothers{The word for 'brothers' here may be also correctly translated 'brothers and sisters' or 'siblings.'}, that this disciple wouldn't die. Yet Jesus didn't say to him that he wouldn't die, but, 'If I desire that he stay until I come, what is that to you?'