[After David summed up the 613 mitzvos in eleven, Yeshayahu in six and Michah in three,] Yeshayahu came again and summed them up in two, as it says, “So says Hashem: Keep justice and do righteousness” (Yeshayahu 56:1). Amos came and summed them up in one, as it says, “So says Hashem to the house of Yisrael: Seek Me and live” (Amos 5:4). Rav Nachman bar Yitzchak objected: Say [it means], seek Me through the whole Torah! Rather, Chavakuk came and summed them up in one, as it says, “And the righteous one will live by his faith” (Chavakuk 2:4).