The story goes like this. There was these 10 lepers. Lepers in those days very kesian one. No cure one. Everyone was afraid of them and they are left to rot in the hills and caves. Away from the community.
One day Jesus pass by an area where there are lepers. They got to know this and shouted for Jesus to have mercy on them.
Jesus heard them and ask his disciples to bring them to him. He healed them and ask them to go and show themselves to the Priest. During those days, they have to show themselves to the Priest to get a confirmation that they are cured. Not like now where you can start go and get Medical Check-up at any hospital.
Well, out of the 10 lepers that Jesus cured. Only one came back to thank him