Hawzah News Agency – The merciful prophet of Islam (pbuh) says:
مَن نامَ علَى الوُضوءِ إن أدرَكَهُ المَوتُ في لَيلِهِ فهُو عِندَ اللَّهِ شَهيدٌ .
'Whoever sleeps with ablution [wodu] and dies in his sleep is regarded by Allah as a martyr.'
Source: Bihar al-Anwar, v. 76, p. 183, no. 7