Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The shield (Turs/Darqa) in a dream is a man who protects his friend from enemies, like a brother or a friend. It is protection from affliction.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The shield indicates a righteous man who prevents evil. Whoever sees a shield in his hand will be saved from his enemy.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The shield is interpreted as a brother or a friend. Whoever sees his shield break, his brother or friend will die.