This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

47,000

1 Machabees 3:38-39 View context

Lysias chose Nicanor, Gorgias, and Ptolemy son of Dorymenes as army commanders; all three were able men who bore the title Friend of the King. He put them in charge of 40,000 infantry and 7,000 cavalry and ordered them to invade the land of Judea and destroy it as the king had commanded.

20,000

2 Machabees 8:9 View context

Ptolemy immediately appointed Nicanor son of Patroclus, who was also in the closest circle of the King's Friends, and sent him with more than 20,000 troops of various nationalities to wipe out the entire Jewish race. Ptolemy also appointed Gorgias, a general of wide military experience, to go with him.