The main strength is in the heart

249 - The main strength is in the heart The main strength [might or heroism] is in the heart, because one whose heart is strong and he does not fear any person and any thing in the world can do awesome strengths and to conquer the wars through the strength and might of his heart that he does not fear and runs into the might of the war. And this is the aspect of: [Avot chapter 4] "Who is strong? He who conquers his inclination". And this is the aspect of strengths of Samson that is said about him: "And the spirit of Hashem began to stir him in the camp of Dan between Zorah and Eshtaol" [Judges 13:25], that in those places the spirit of Hashem succeeded upon him and he donned strength, that is, that there came to him strength and might of strength in the heart. And through this he did awesome strengths.