Halakhah zu Dewarim 13:15

The commandment of investigating the witnesses well: To make a formidable investigation of the testimony and to inquire about it well according to all of our ability, so as to known the root of a thing and its completely exact truth. And from the foundation of this matter, they, may their memory be blessed, said (Avot 1:1), "Be deliberate in judgment." And it is all so that we can reflect on the thing and know the truth about it; and that we not hurry in judgement, lest we kill the innocent and cause a loss of money, because the truth is concealed. And about this is it stated (Deuteronomy 13:15), "And you shall inquire and investigate and ask well, and behold, the thing is correct truth." And anyone who has eyes in his head will observe and see that the multitude of warnings and repetition of the matter in different words that the Torah repeated about this thing is is to properly warn us about the matter; as it is a great thing and a strong pillar upon which the blood of the souls of the creatures depends.