The fact that there are two lions is a “heraldic pun” on the Bishop’s family name, Thomas.
Designing his shield - the central element in what is formally called the heraldic achievement - a bishop has an opportunity to depict symbolically aspects of his life and heritage, and elements of the Catholic faith that are important to him. Every coat of arms also includes external elements that identify the rank of the bearer. The formal description of a coat of arms, known as the blazon, used a technical language, derived from French and English terms, that allows the appearance and position of each element in the achievement to be recorded precisely.
A diocesan bishop shows his commitment to the flock he shepherds by combining his personal coat of arms with that of the diocese, in a technique known as impaling. The shield is divided in half along the pale or central vertical line. the arms of the diocese appear on the dexter side - that is, on the side of the shield to the viewer's left, which would cover the right side (in Latin, dextera) of the person carrying the shield. the arms of the bishop are on the sinister side - the bearer's left, the viewer's right.
The diocese is officially known as the Diocese of Toledo in America, to distinguish it from the city and archdiocese of the same name in Spain. That Toledo is the capital of the province of Castilla-LaMancha, whose coat of arms depicts a triple-towered castle painted gold, on a red field. By changing the color of the castle to white (often painted silver and called argent), and dividing the field vertically (per pale) red (gules) and blue (azure), the diocesan coat of arms includes the three heraldic colors of the United States of America.
The blue and silver in the personal arms of Bishop Thomas allude to the arms of the Archdiocese of Philadelphia, where he was ordained a priest in 1985, and a bishop in 2006. The field is partitioned per cross, dividing the shield into four quarters of alternating colors. Thus the Cross of Christ is at the center and foundation of the shield, as it should be the center and foundation of the life of the bishop and of every Christian.
The lions on the shield recall Bishop Thomas' baptismal patron saint, the Prophet Daniel. The Book of Daniel (6:2-29) relates how King Darius forbade his subjects - including the Israelites in exile in Babylon - to pray to any god or power other than himself. When Daniel was found praying to the Lord, he was thrown into a den of lions. The next day he emerged alive and "unhurt because he trusted in his God" (Daniel 6:24).
The fact that there are two lions is a "heraldic pun" on the Bishop's family name, Thomas. This was also the first name, of course, of one of the Twelve Apostles, whom the Gospel of John (11:16; 20:24) refers to as "Thomas, called Didymus," a Greek name meaning "twin." The "twin" lions on the shield thus call to mind the apostle known as "the Twin."
The motto, placed on a scroll below the shield, also refers to Saint Thomas. Although disbelieving at first, when he beheld the risen Lord Jesus he confessed his faith by declaring, "Dominus meus et Deus meus" - "My Lord and my God" (John 20:28).
The shield is ensigned with external elements that identify the bearer as a Bishop. A gold processional cross appears behind the shield; it is chased as jewelled with five gems recalling the five wounds of Christ. This too alludes to Saint Thomas, whom Jesus invited to put his fingers into the nail marks in his hands and the wound in his side. The galero or "pilgrim's hat" is used heraldically in various colors and with specific numbers of tassels to indicate the rank of a bearer of a coat of arms. A bishop uses a green galero with three rows of green tassels.