Dreaming of performing Tayammum signifies that you are nearing a resolution to some problems in your life. When you see yourself doing Tayammum without water, it indicates that solutions to your current issues are on the horizon. This dream may also symbolize a change in your life, where you are seeking new perspectives or approaches. Additionally, it reflects your confidence and determination, which will aid you in moving forward.
From Imam Muhammad Ibn Seerin's Dictionary of Dreams According to Islamic Inner Traditions â entry "Tayammum" (page 430).
Performing one's ritual ablution but without water in a dream means the nearing solutions of one's problems. Tayammum is usually performed instead of the regular ablution in the absence of water, or because of a preventing illness, etcetera. However, observing the religious rites and substance ofthe act remains solemn. Tayammum in a dream also may mean a journey, or an illness. If the act is performed with a dry surface such as wood, stone, dry sand, earth, or a substance that does not stick to the skin in a dream, it means that one's travel plans may be infeasible, or it could mean that he will become cheep, or pursue his evil desires. To perform tayammum while water is accessible in a dream means falsehood and hypocrisy. It also means hoping for forgiveness while adamantly pursuing the avenues of wrongdoing, giving preference to one's interests. in the world over his lasting benefits in the hereafter, preferring masturbation over lawful sexual intercourse, or being a hypocrite, and it could mean recovering from a terminal illness, or release from prison. (Also see Enacting; Ablution)
Note: Islamic dream interpretation depends on the dreamer's circumstances and state. This is a general guide drawn directly from the source book.