Matthew the apostle and the angel

St. Matthew often appears in Christian art among the four evangelists.

Saint Matthew | History, Facts, Feast Day, & Death | Britannica

When the evangelists are represented only by symbols, especially in the earlier art, Matthew's symbol will be an angel (example). When they are presented as men with attributes, the angel will be Matthew's attribute (example), often a small one standing at his left foot (example). See the page for the evangelists.

Many group portraits of the apostles give keys and a sword to Peter and Paul respectively and leave the others generally without attributes (example).

When St. Matthew does have an attribute in such portraits, it may be a book and/or a sword or halberd (example).

Apostle Matthew - OrthodoxWiki

The sword is the weapon with which the Golden Legend says he was killed. The halberd seems to have no textual basis. Duchet-Suchaux (241) suggests it may be a way to distinguish him from St. Paul, or it could arise from a confusion with St. Matthias, whose axe can resemble a halberd. See the page for the apostles File : Evangelist-St.-Matthew-And-The-Angel.jpg FUQAM