Verses with the word horseback in the Apocrypha (3 verses):

Judith 2:15
And he mustered the chosen men for the battle, as his lord had commanded him, unto an hundred and twenty thousand, and twelve thousand archers on horseback;

2 Maccabees 11:8
And as they were at Jerusalem, there appeared before them on horseback one in white clothing, shaking his armour of gold.

2 Maccabees 12:35
At which time Dositheus, one of Bacenor's company, who was on horseback, and a strong man, was still upon Gorgias, and taking hold of his coat drew him by force; and when he would have taken that cursed man alive, a horseman of Thracia coming upon him smote off his shoulder, so that Gorgias fled unto Marisa.