You had approached Kharjo with his lost Moon Amulet, that was stolen from him by the Bandit Camp he sent you to,

"There it is. Ah.... Home.... If you ever need the skills of a Khajiit warrior by your side, I would be honored to travel with you. Until then, here. This is for you, in thanks."

He was truly greatful, and wasn't expecting you would return, as he nodded in thanks.