En bref
Matthew uses the word behold
(idou) to stress the importance of the Magi’s arrival in the capital city Jerusalem, as special messengers, passing on their revelation of the birth of the king of the Jews.
With the word behold
(idou), Matthew draws the reader’s attention to the arrival of the Magi in the capital city. God used them as special messengers for Jerusalem.1 The wise men came to Jerusalem precisely because it was revealed to them that the king of the Jews had to be born there.2
1 Jésus étant né à Bethléhem en Judée, au temps du roi Hérode, voici des mages d'Orient arrivèrent à Jérusalem,