Deuteronomy 20:3

And David said to Saul, “Let no man’s heart fail on account of him; your servant will go and fight with this Philistine.”

and he said, “Pay attention, all Judah and the inhabitants of Jerusalem and King Jehoshaphat: thus says Yahweh to you, ‘Do not fear or be dismayed because of this great multitude, for the battle is not yours but God’s.

“It is God who has made my heart faint, And the Almighty who has dismayed me,

and say to him, ‘Take care and stay quiet, have no fear and do not be fainthearted because of these two stubs of smoldering firebrands, on account of the burning anger of Rezin and Aram and the son of Remaliah.