Grading: This chain is "da'if" (weak) because of a break (inqita').
Technical note / Defect ('illah): Muhammad bin Ishaq (bin Yasar) did not hear this hadith directly from Imam al-Zuhri. Ibn Abi Hatim narrated in "al-Jarh wa al-Ta'dil" (1/ 330) from Imam Abu Zur'ah al-Razi that Ibn Ishaq heard this hadith from Mu'awiyah bin Yahya al-Sadafi when he was accompanying him on the journey from Iraq to Rayy (the city), and it is this Mu'awiyah who narrates it from al-Zuhri, and he is "da'if jiddan" (very weak).

Reference / Source: This narration is in "Musnad Ahmad" 43/ (26340) through Ya'qub bin Ibrahim (bin Sa'd), with this same chain.

Corroborating chains and supporting reports: Narrations with a meaning similar to this hadith are reported from several narrators, both connected (muttasil) and mursal, as mentioned in Ibn Daqiq al-'Id's "al-Imam" (1/ 364-368) and Ibn al-Mulaqqin's "al-Badr al-Munir" (2/ 13-20), but none of their chains is free from criticism (weakness).
Important point: Imam al-Sakhawi said in "al-Maqasid al-Hasanah" (625) that some of its routes strengthen others, and for this reason Diya' al-Din al-Maqdisi included it in "al-Mukhtarah".
Technical note / Defect ('illah): The statement of Yahya bin Ma'in that Imam Ibn 'Abd al-Barr quoted in "al-Tamhid", that it is a "false (batil) hadith", was with regard to the particular routes that had reached him.