The Scottish champions agreed a fee with FC Ashdod to bring the Israeli midfielder to Celtic Park on Wednesday, completing the transfer earlier today.
The 21-year-old told the Hoops' website: "I don't think I needed something to convince me to come to a club the size of Celtic. It is a big club in Europe and has one of the best sets of fans in the world. This is my dream.
"I know the level of club Celtic are so I didn't need to speak to anyone before coming here. I'm now at Celtic, one of the best clubs in Europe, and I will try to play my best for the fans and to improve myself. I hope it will be good.
"The fans were something I have never seen before. I want to be the best and my dream is to play for Celtic and be a success for them. Playing in the Champions League is a dream for every player."
Celtic were drawn in a group with Barcelona, AC Milan and Ajax for the Champions League.