Audi filia et vide and De sinu patris

Audi filia et vide and De sinu patris are 13th-century papal letters addressed, respectively, to a widowed queen of Cyprus and a married nobleman of the Kingdom of Jerusalem. In the letters, a pope rebukes unnamed recipients for maintaining an extramarital relationship. Because neither letter is dated, their authorship and the identities of the individuals involved have been the subject of prolonged scholarly discussion. The letters have variously been attributed to Urban IV, with proposed dates of 1261 or 1262, or to Clement IV, dated to 1267 or 1268.

The nobleman, referred to only as "Count J.," is described as the husband of a sister of the king of Cilicia, a description that fits John of Ibelin, count of Jaffa. A contemporary marginal note characterizing the relationship as incestuous has been cited in support of identifying the queen as John's kinswoman Isabella of Ibelin. Since John died in 1266, a year before Isabella became a widow, it has also been proposed that the nobleman was instead Julian Grenier, lord of Sidon and son-in-law of the Cilician king.

One version of the letter to the nobleman names the bishop of Bethlehem as papal legate. As the bishop of Bethlehem held this office during the pontificate of Urban IV, this detail has been taken by modern historians as supporting attribution of the letter to Urban and identification of its recipients as John of Ibelin and Plaisance of Antioch, who died in 1261. Plaisance, queen of Cyprus, ruled the Kingdom of Jerusalem as regent, while Count John held a dominant position among the kingdom's nobility; the affair is interpreted as a mutually beneficial relationship meant to further the couple's political goals.