If you see a mirage in your dream, it signifies confusion or falsehood. It indicates that what you desire may not be attainable or may not materialize in reality. This type of dream may prompt you to reevaluate your aspirations, as the illusion presented could represent things in your life that are unrealistic or unattainable.
From Imam Muhammad Ibn Seerin's Dictionary of Dreams According to Islamic Inner Traditions â entry "Mirage" (page 280).
In a dream, a mirage represents falsehood, or some thing that will not take effect. If one desires something, then sees a mirage in his dream, it means that his desire is impossible to attain, or that he will be deprived from attaining it. A mirage in a dream also represents hypocrisy and ingratitude, disbelief in God's oneness and love to amass the world and to indulge in its pleasures. A mirage in a dream also may denote false hopes, or unattainable goals. If one is summoned by the court to testify in a case, and if he sees a mirage in his dream, it also means that he will give a false statement. A mirage in a dream also represents a story that has no basis, or deception and
lies that are reported as if they were true. (Also see Ghost)
Note: Islamic dream interpretation depends on the dreamer's circumstances and state. This is a general guide drawn directly from the source book.