Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The coffin (or ark) in a dream indicates a man's house, his wife, or his heart that holds his secret. Whoever sees himself in a coffin will gain great authority, kingship, and prestige.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The coffin indicates tranquility, dignity, and sustenance. For the worried, it is relief, and for the fearful, security. Whoever finds a coffin has found a treasure or knowledge.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The coffin is interpreted as kingship and high status. Carrying it indicates serving the ruler. Whoever sees himself making a coffin is building a house or getting married.