The registration of these people was therefore conducted with bitter haste and zealous intentness: The people doing the registration are the scribes (see the previous verse). The phrase with bitter haste and zealous intentness is probably intended to accent the miracle that will save the Jews (verses 20-21). After receiving the king’s orders, the scribes did what they were told. They registered the Jews quickly, but carefully, with a bitter attitude. We may translate this clause as “So the scribes began to record the names of these people. They did it as quickly and carefully as they could [or, as possible], and with a bitter attitude.”

From the rising of the sun till its setting means the scribes registered the Jews from the first light of the sun in the morning until it was too dark to write. We may say “They worked at it from the time the sun rose [or, dawn] till the time it set [or, dusk].”

And though uncompleted it stopped after forty days may be rendered “but after forty days they had not finished their work yet.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 3-4 Maccabees. (UBS Helps for Translators). Miami: UBS, 2018. For this and other handbooks for translators see here.