The One Where Ross Got High - S6-E9
Rachel: You guys, it was bananas, cream, and beef! I just cannot believe that you ate that so that I wouldn't feel bad.
Monica: Actually, I didn't eat mine. It's still in the bathroom.
Joey: No, it isn't. I ate that.
Judy: And we left ours in Monica's bedroom.
Joey: No. Got it, [nods to Jack] and got yours, too.
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.