The four epigraphs on the back wall, in white marble with mistilinear scrollwork frames, come from the ancient Baroque side altars of the Baptistery. Between 1732 and 1742, Girolamo Ticciati renovated the main altar of St. John and subsequently created two minor altars: one dedicated to Mary Magdalene on the southeast side, and the other to the Holy Crucifix on the northeast side. These two altars were twins, with niches that housed Donatello’s Mary Magdalene in the former and a wooden crucifix attributed to Cosci in the latter (today placed facing each other in the Magdalene Room). The niches’ frames were in polychrome marble and crowned with pediments, with the altars positioned below them. The smaller epigraphs were in the pediments, while the larger ones were placed beneath the altar between pairs of Calimala eagles.

The epigraph on the Magdalene altar reads “DILEXIT MULTUM” (“she has loved much”), a quote from the Gospel of Luke (7:47), referring to this biblical figure to whom the altar is dedicated. It states that her sins were forgiven because she loved much—a concept that also evokes the purifying function of Baptism, administered in this temple. The lower epigraph (now in the Magdalene Room) commemorated the creation of the altar in 1735: “For public vow, the statue of Mary Magdalene, an exquisite work by Donatello, was returned to its original location and gracefully repositioned in the year 1735.” The epigraph on the pediment of the Crucifix altar reads “IN MORTE IPSIUS BAPTIZATI SUMUS” (“We were baptized into His death”), a passage from St. Paul’s Letter to the Romans (6:3), where the crucifixion of Christ (to whom this altar is dedicated) is associated with Baptism, administered in this place. The epigraph below the altar commemorated the privilege granted by Pope Clement XII in 1740, offering universal suffrage for five years to those celebrating the Mass for the Dead on this altar.