Spell:Avani's Resuscitation

Birthright spell

An extremely powerful healing spell available only to priests of Avani and Laerme, all those near the priest and in the daylight regenerate swiftly.

An extraordinarily powerful healing spell, all beings within 100 yards of the caster and in daylight heal at 1 hit point per turn while they are in the area of effect. The spell also cures blindness/disease in an hour, regenerates limbs in 4-12 hours and raises the recently dead after they 'heal to -10 hit points' (i.e. are restored from whatever damage they had, to a point that they are biologically able to live, assuming of course that they are mostly intact). If the spell expires, or the fallen persons leave the area of effect before they are healed to reach 0 hit points, the fallen person is treated mechanically as though they had just stabilized at their current negative hit point level leaving them still at death's door. Source: BoP.

The prayer is almost legendary in Khinasi lands, and any priest who casts the spell gains great sayim. By order of the Great El-Arrasi, echoed by all temples of Avani in the Khinasi lands, it is socially unacceptable for any to harm a being healed by the spell for a full day afterwards - they have been filled with Avani's grace and to harm them, or seek to restrain them in any way, would be an offense against Avani herself. The bandit king Farid ibn Malikai was thus permitted to walk from the battle of Khomein's fields in which the Paladin-king of Ariya destroyed his host without harm, the experience of being raised from the dead by Avani's grace had a profound effect on the bandit however, and he turned away from his former life, becoming a priest of Avani and eventually famed as the Seer of Merasaf, known far and wide for his humility and wisdom.

The spell is a battlefield spell, used to restore the health of hundreds, even thousands of warriors. Typically the wounded and dying are brought to a single place for bandaging and the priest stays in that location to ensure that all brought there are healed. If the battlefield is less organized, the priest typically slowly walks the field with the healing sunlight about them aiding the fallen warriors.
The spell allows the sun to shine brightly even through thick clouds, as such it can have tactical considerations in battles against orogs, undead, etc on cloudy or foggy days by exposing such beings to sunlight.

As an AD&D spell, this is a quest spell with the healing sphere.