Matthew counts his list into three sets of fourteen, and has to leave out kings to do it.
Fourteen, fourteen, fourteen
Matthew’s scheme requires omitting Ahaziah, Joash and Amaziah, and probably Jehoiakim; and the third section has thirteen names unless one is counted twice. Fourteen is the numerical value of David’s name in Hebrew (4+6+4), and 3×14 = 6×7, placing Jesus at the start of a seventh seven.
The texts
17So all the generations from Abraham to David are fourteen generations; from David to the exile to Babylon fourteen generations; and from the carrying away to Babylon to the Christ, fourteen generations.
10Solomon’s son was Rehoboam, Abijah his son, Asa his son, Jehoshaphat his son,
11Joram his son, Ahaziah his son, Joash his son,
12Amaziah his son, Azariah his son, Jotham his son,
On the chart
Numbers count from Adam as 1, following the critical Greek text, which reads Admin and Arni where the WEB has Aram (hence 27–28). Gold numbers fall on multiples of seven: Enoch 7, Abraham 21, David 35, Jesus 77.
In the tradition
Ahaziah, Joash, Amaziah · Patristic Jerome says the three were left out because Joram married into the house of ‘the most impious Jezebel’, whose memory is removed to the third generation (Commentary on Matthew 1:8, PL 26:22D–23A). Hilary gives a different reason: a prophecy that the house of Ahab would not hold the throne past the fourth generation (Commentary on Matthew, PL 9:920B–921A).
David · Numerology In Hebrew the consonants of David (דוד) have the values 4 + 6 + 4 = 14. Many readers since the Middle Ages have taken Matthew’s three fourteens as a signature of David; Matthew never says so.