Dreaming of a clay jar signifies the presence of someone in your life who may seem trustworthy but could actually deceive you. This dream serves as a warning, especially if you are involved in business. On the other hand, drinking clear water from a clay jar symbolizes achieving success through your hard work. It can also indicate positive changes coming into your life.
From Imam Muhammad Ibn Seerin's Dictionary of Dreams According to Islamic Inner Traditions â entry "Jar" (page 230).
In a dream, an earthenwarejar represents a deceiving employee who is entrusted with the accounting department of one's business. Drinking fresh water from an earthenware jar in a dream means earning lawful money and comfort in one's life. Drinking half of the water contained in a jar in a dream means having consumed half one's life span. Drinking from a tight mouthed earthenware container in a dream also means
tempting a female worker. If one's wife is pregnant and he sees himself carrying an earthenware jar that falls and breaks, it means that his wife may die from complications during her delivery or after giving birth to the newborn. In a dream, an earthenware jar also can be interpreted as a hard-working woman, or a servant, though a copper jar represents a noble woman. Ajar of wine in a dream represents woman's menstrual period. If one drinks from a jar of wine, it means that he will have sexual intercourse with his wife during that period, which act is forbidden in Islam. Ifthejar is filled with eating oil, honey, or milk, it represents a hidden treasure. The same interpretation applies for a small clay jug, a mug, a cooking earthenware, or a tin pot. (Also see Pot)
Note: Islamic dream interpretation depends on the dreamer's circumstances and state. This is a general guide drawn directly from the source book.