Al-Husayn ibn Sa’id, from Fadala, from Al-Ala ibn Razin, from Muhammad ibn Muslim, narrated from one of the Imams عليه السلام: Imam عليه السلام was asked regarding a man who becomes junub (in a state of major ritual impurity) while on a journey and has only enough water for wudu (ablution). Imam عليه السلام said: "He should perform tayammum (dry ablution) and not perform wudu."