The words “a righteous man before Me” are somewhat puzzling. It would seem implied that there existed during that time other righteous individuals, who despite their being honorable and virtuous, lacked the requirements of “righteous before Me“. We may derive from here a noteworthy lesson. It is perhaps possible for one to be a moral and upright individual, even righteous and G-d fearing. However, there is a more sublime plateau of righteousness, this being the ability to stand before Hashem’s scrutiny and nevertheless be viewed as a tzadik. This is defined as “righteous before Me” – a tzadik who remains virtuous even under Hashem’s examination. This was the unique level attained only by Noach.
