Musar su Salmi 18:38

The sages of blessed memory said David was watchful and cleansed himself completely from all these things. Therefore, he would engage in war with strong trust in G-d requesting "May I pursue my enemies and overtake them, not turning back till I have destroyed them" (Tehilim 18:38), something not asked by Yehoshafat, Asa, and Chizkiyahu since they had not attained such perfect cleanliness (see Midrash Eicha Raba peticha 30).

CLEANLINESS FROM THEFT: We can observe that even though most people are not blatant thieves, literally taking with their hands the possession of their fellow and putting it in their own possessions, nevertheless, most people experience a taste of theft in their business dealings by rationalizing permission to profit through their fellow's loss. They may tell themselves: "Business is different".

For it is not only the explicit and well known deed of theft or oppression which is forbidden but rather anything which may eventually lead to such a deed and cause it is included in the prohibition. On this our sages of blessed memory said (Sanhedrin 81a): "'he did not defile the wife of his fellow' (Yechezkel 18:6) - that he did not encroach upon his fellow's trade".