Antidotes......

During the singing of the Psalm, the priest distributes pieces of holy bread. These are the remnants of the oblation-loaf out of which a portion - the Lamb - has been cut in memory of Christ, and is called Antidoron, which means: "Substitute for the Gift." The Antidoron is distributed in order that those who have not received communion may also, as least, in thought, share in the Sacrament of the Eucharist, that they may not feel left out of the community of the faithful, but in communion with them. The distribution of the Antidoron is a survival of the agapes or love-feasts which, among the early Christians, were made up of the remains of the offerings brought.

A Manual of the Orthodox Church's Divine Services, Archpriest D. Sokolof