What does the Jew mean with his claim to 'Umar bin Al-Khattab in Sahih al-Bukhari 45?

Question

Sahih al-Bukhari 45:

Narrated 'Umar bin Al-Khattab:

Once a Jew said to me, "O the chief of believers! There is a verse in your Holy Book Which is read by all of you (Muslims), and had it been revealed to us, we would have taken that day (on which it was revealed as a day of celebration." 'Umar bin Al-Khattab asked, "Which is that verse?" The Jew replied, "This day I have perfected your religion For you, completed My favor upon you, And have chosen for you Islam as your religion." (5:3) 'Umar replied,"No doubt, we know when and where this verse was revealed to the Prophet. It was Friday and the Prophet (ﷺ) was standing at 'Arafat (i.e. the Day of Hajj)"

1. Speech of the Jew is not translated clearly, so what is the correct translation?

2. What does the Jew mean with his claim?

Edit:

3. This hadith is in the book of Iman of Sahih al-Bukhari. What does it teach to us?

Answer 1

The translation is pretty clear, and I don't see any improvement in it.

The Jew is saying that the statement by Allah "This day I have perfected your religion For you, completed My favor upon you, And have chosen for you Islam as your religion" was something he would have been so happy with if it had been revealed about his religion that he would have taken that day as a day of celebration.