Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The lock in a dream is a trustworthy man, religion, or an argument. Opening it indicates the facilitation of matters and the removal of worry. An iron lock is a knowledgeable man, and a wooden one is a hypocritical man.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The lock indicates a virgin woman for the unmarried. It may also indicate heedlessness and misguidance. Opening a lock is relief from worry and payment of debt.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The lock is interpreted as a guardian. Whoever sees himself opening a lock will get married or his worry will be relieved.