Kids say the darndest things

Matthew was not cooperative eating breakfast this morning, so I left him in the breakfast area and brought Scarlett to play. As we are playing I can hear him talking to himself. All of a sudden I hear him say "hold your horses". I think it's so funny to hear him say something like that and wonder where he came up with it. He's really not around other adults a lot, just me & David so I guess one of us says it, although I can't recall us using it. He also has a habit of saying "hmmm" when he's thinking or when he notices something. Well since we've talked about him saying it, David has pointed out several instances when *I* have said "hmmm" so I guess he gets that from me.