הלכה אויף ירמיהו 17:10

And so that your heart should not trouble you when you see or examine what we are about to write here, and you might say, “These are not words of piety, but merely superstitions,” do not let this thought arise in your heart, and do not be misled into thinking this way. For this book is called Sefer Chasidim (The Book of the Pious), and its name reflects its true nature.

“I, the Lord, search the heart and examine the kidneys” (Jeremiah 17:10).