1 Samuel 17:16

And the Philistine drew near morning and evening
Twice a day he came near the camp, within the hearing of it. The Jews ^F23 say, he took those seasons on purpose to disturb them in reading their "Shema", or "hear, O Israel" and saying their prayers morning and evening:

and presented himself forty days;
Successively, before the armies of Israel, daring them to send down a man to fight with him, and reproaching them for their cowardice in not doing it.