Together with vows and freewill offerings this was one of the three kinds of fellowship offering.
Presenting a thank-offering
Accompanied by bread, wafers and cakes Lev 7:12-13 Cakes made with yeast can be offered, since these are not to be burned on the altar.
The occasions for presenting thank-offerings
For deliverance from distress, death or sickness Ps 50:23; Ps 107:21-22 See also Ps 56:12-13 deliverance from death; Ps 116:17 Deliverance from sickness; the earlier verses show the psalmist has been ill.