Surely he knows your imaginations and what you think in your hearts!: Compare Psa 44.21. Here Ezra speaks directly to his people. Good News Bible makes this clear by beginning this clause with “My people,” but this is not necessary. The Latin pronouns for your and you are plural. The phrase your imaginations may be combined with what you think in your hearts by rendering this clause as “He certainly knows your own most secret thoughts” or “The Lord himself knows exactly what you are secretly thinking.”
Woe to those who sin and want to hide their sins!: For the word Woe, see the comments on 2 Esd 2.8. This clause may be translated “Sinners who try to hide their sins are doomed” (Good News Bible) or even “He will punish those people who try to hide their sins from him.”
Because the Lord will strictly examine all their works, and will make a public spectacle of all of you: Compare 2 Esd 7.37, where God’s judgments are made in public. Make a public spectacle of means basically “expose.”
The writer shifts from second to third person for people in the middle of verse 63, then shifts back to second person at the end of verse 64. Good News Bible uses second person (plural) throughout these verses. This makes for easier reading, and we are following it in this model:
• 63 He certainly knows your own most secret thoughts! If you sin but try to hide your sin, you face a tragic end [or, the Lord will punish you], 64 because the Lord [or, he] will look closely at every thing you do. He will find every sin you ever committed and bring them to light.
Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.
