A dove returned to Noah with an olive leaf after he released it from the Ark. Genesis 8 describes Noah sending out birds as he waited for the floodwaters to recede.
The sequence begins with a raven, which Noah released and which went back and forth until the waters dried up. Noah then sent a dove, but it initially found no place to land. After seven days, he sent the dove again, and it returned with a freshly plucked olive leaf. A later release produced no return, showing Noah that the land was becoming habitable.
The dove and olive branch have become widely recognized symbols of peace and hope. That symbolism comes from the biblical scene but is broader than the original practical sign: in Genesis, the leaf primarily tells Noah that vegetation has reappeared.
The dove is sometimes confused with the first bird mentioned in the account. Genesis names the raven first, but the bird carrying the olive leaf is specifically a dove.