Matthew 1:8

Joram begot Ozias, three generations are omitted, as we find 2 Paraliponenon xxii; for there, Joram begot Ochozias, and Ochozias begot Joas, and Joas begot Amazias, and Amazias begot Ozias. This omission is not material, the design of St. Matthew being only to shew the Jews that Jesus, their Messias, was of the family of David; and he is equally the son, or the descendent of David, though the said three generations be left out: for Ozias may be called the son of Joram, though Joram was his great-grandfather. (Witham) --- It is thought that St. Matthew omitted these three kings, Ochozias, Joas, and Amazias, to preserve the distribution of his genealogy into three parts, each of fourteen generations; and, perhaps, also on account of their impiety, or rather on account of the sentence pronounced against the house of Achab, from which they were descended by their mother Athalia. (3 Kings xxi. 21.) (Calmet)