Where did the custom of giving eggs originate?

from chickens In most birds and reptiles, an egg is the zygote – a cell that is the result of fertilization. That is, two haploid cells — usually an ovum from a female and a sperm cell from a male — merge into a single diploid cell called the zygote. To enable incubation the egg is usually kept within a favourable temperature range as it nourishes and protects the growing embryo. When the embryo is adequately developed it breaks out of the egg in the process of hatching.