Source: The Great Interpretation of Dreams (Ibn Sirin)
A sandal in a dream indicates a wife, brother, partner, travel, or riding animal. Wearing it indicates embarking on one of these matters. Taking it off is security and authority. Walking with one sandal is separation.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A sandal indicates protection, strength, and power. It indicates a woman or travel. Losing it indicates worry and separation.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A sandal is interpreted as a woman or a servant. Whatever good or bad is seen in it reflects on them.