Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Swallowing things in a dream indicates greed and avarice. Swallowing pearls indicates concealing knowledge. Swallowing a dinar (gold coin) indicates concealing true testimony.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Whoever sees himself swallow something is keeping a secret. Swallowing what is not edible indicates worry and grief.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Swallowing is interpreted as wealth. Whoever sees himself swallow something good will gain lawful wealth.