If I sell something to the "X", and "X" said me that he doesn't have all the money right now so, he gives me the half of the money and MR "X" also

If I sell something to the "X", and "X" said me that he doesn't have all the money right now so, he gives me the half of the money and MR "X" also promise me that when he paid me full of the amount he take the merchandise. So, MR "X" said me to keep the merchandise until he paid me full. One day one person stolen the merchandise for my warehouse. In this particular situation, who take the loss of the merchandise. ME or Mr "X" ? and if we claim who will win the claim ME or MR "X" ?