The former England international, who has been training with his former team following his exit from Besiktas, disclosed that his former Arsenal team-mate persuaded him that a stint in Glasgow would be a great fit.
Oxlade-Chamberlain said: "I spoke with him about it and he just explained how much of a perfect fit it would be.
"His words were that his time up here was some of the best of his career.
"He felt things that he didn't necessarily feel again, even at other big clubs that he played for. He talked highly of the rivalry, the passion, and what it means to everyone that's around here."
Oxlade-Chamberlain said: "He said it's a massive place, a massive club, and it will be an amazing fit.
"He spoke very highly of everything up here and how things go. That also helped to hear it from his side of things."
In his recent sit-down with Celtic TV, Oxlade-Chamberlain also commented on his current fitness status.
He said: "I'm ready. I've been training for three months at Arsenal and running around there, and keeping up with those boys.
"That has been really helpful for me to keep me in a rhythm and fit."
He added: "The next step is playing games, and there is a different intensity to that.
"I'm ready to do that. It will take a little bit of time as it always does to get flying to your full match fitness, but in terms of being ready to go now, I'm good to go and excited."