The expression, which literally reads this your strength,
is ambiguous. There are a couple options. It could refer to the “strength of character that Gideon has just shown by challenging what the messenger said to him: he may be wrong, but he is not weak. More likely, however, Yahweh simply ignores what Gideon has said and continues from where he (as the messenger) left off in verse 12. The important thing is not how Gideon himself thinks or feels, but what God has declared him to be: a mighty warrior (v. 12). His strength lies in his being chosen by God, and in God’s promise to be with him.”1
14 And the LORD turned to him and said, “Go in this might of yours and save Israel from the hand of Midian; do not I send you?”