The midfielder turned down a move to Barcelona last summer.
"When you are shown affection at your home then you don't go to the other side," he told L'Equipe Magazine.
"They did everything possible for me at the club to make me feel good, including the efforts to sign important players and to build a great squad.
"I feel like the foundation or the most important piece of the puzzle.
"That's what made me stay.
"It's often said that you do not say no to Barcelona, but I did the opposite.
"It is difficult to say no to clubs like Barcelona, but I'm really happy here.
"It is my home and I want to do great things."