Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Drowsiness in a dream is security from fear. It indicates righteousness in religion and worldly life.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Drowsiness indicates guidance after misguidance. For the sick, it is healing.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Drowsiness is interpreted as security. Whoever sees himself drowsy is safe from what he fears.