Moab hath been at ease from his youth, and he hath settled on his lees, and hath not been emptied from vessel to vessel, neither hath he gone into captivity: therefore his taste remained in him, and his scent is not changed.
Moab has been comfortable since childhood, staying in one place without being emptied or moved from one container to another. He hasn't experienced capture either. So, his flavor and smell have stayed the same.