Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Ablution in a dream is a trust fulfilled, a debt paid, or a testimony given. It is light and purification from sins. Whoever sees himself performing ablution with impure water is in worry and grief. Completing the ablution indicates achieving one's goal.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Ablution indicates relief from worries. For the sick, it is healing, and for the sinner, repentance. Ablution with hot water indicates illness or worry.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Ablution is interpreted as security and relief. Whoever sees himself performing ablution has emerged from worry. If he does not complete his ablution, his affair will not be completed.