It says in the verse “You should be simple with Hashem your G-d.” and likewise “One who goes simply, goes in surety.” With this our father Yaakov was praised as it says “and Yaakov was a simple man” and in Iyov it says “a simple and straightforward man”. The point of simplicity is that he should not try to know the future through lotteries and magic and likewise. He should not be sorry for the sorrows of tomorrow but should throw his burden upon G-d. He should not try to know what is in the heart of is friend and he should not go in the path of trickery and deceit to turn after corruption. Instead, he should go in the simple ways of the righteous and not think about the matters of this world and about the matters of his livelihood, but the Torah of G-d should be his desire and he should speak about it by day and night. G-d will not withhold good from those who go in simplicity and those who seek G-d will never lack for good.
י״ג באדר ה׳תש״פ
My brother and my nation, take this Torah book, in this and like this learn well, listen and revival your soul, you will achieve joy and joy, in this world and next world. (from introduction of the author) 1