Next, David expresses confidence that God would hear his prayer, saying: “By this I do know that you have found delight in me, because my enemy does not shout in triumph over me.

Ps. 41:11, 12.

That God had taken delight in the psalmist was evident “by this,” namely, by the fact that God gave him internal assurance that his enemies would not “shout in triumph” over him as victorious fighters in war.