'Desert' in the Bible

Meanwhile, Joab and Abishai continued to chase Abner. At dusk, as they approached the hill of Ammah that is located near Giah on the way to the Gibeon desert,

"I'll catch him while he is still tired and weak. I'll frighten him so all his people with him desert him. But I'll only kill the king.

Now Ahithophel's advice that he provided at that time was being compared to one who inquired of God, so highly regarded was Ahithophel's counsel by both David and Absalom.