Is "Consult your heart, even if people give you a fatwa" a Prophetic hadith or a saying transmitted from the righteous predecessors?

The Hadith about which the question was posed is mentioned by Al-Nawawi in his "Forty Hadiths" on the authority of Wabisa ibn Ma'bad, who asked the Prophet, peace and blessings be upon him, about righteousness (al-birr) and sin (al-ithm). The Prophet said to him: "Consult your heart. Righteousness is that about which the soul feels tranquil and the heart feels at ease. And sin is that which wavers in the soul and causes uneasiness in the chest, even if people give you a fatwa (religious verdict) and they pronounce it permissible for you." Al-Nawawi commented that it is a Hasan Hadith (good Hadith), and it was narrated by Ahmad and Al-Darimi with a Hasan chain of narration. Ibn Rajab and Al-Albani also deemed it Hasan.