Grading: This narration is "sahih li-ghayrihi" (sahih due to its supporting reports).
Technical note / Defect ('illah): All the narrators of this chain are thiqah (trustworthy), but there is disagreement in its narration from Hammad bin Salamah over "wasl" (the chain being connected) and "irsal" (the chain being mursal). Hajjaj bin al-Minhal narrated it from Hammad bin Salamah as "mursal" (from 'Urwah, disconnected), and a group of trustworthy narrators also narrated it from Hisham bin 'Urwah, from his father ('Urwah bin al-Zubayr), as mursal, as will come.

Reference / Source: Al-Tahawi narrated it in "Sharh Ma'ani al-Athar" 4/ 276 through the route of Hajjaj bin al-Minhal, from Hammad bin Salamah, from Hisham bin 'Urwah, from his father 'Urwah bin al-Zubayr, as "mursal".

Reference / Source: Ma'mar bin Rashid narrated it in his "Jami'" (19598), and through his route al-Bayhaqi recorded it in "Shu'ab al-Iman" (5620). Musaddad also narrated it, as in al-Busiri's "Ithaf al-Khiyarah" (3713), from 'Abd Allah bin Dawud al-Khuraybi, and al-Bayhaqi narrated it in "al-Sunan al-Kubra" 7/ 285 through the route of 'Abd al-Rahman bin Abi al-Zinad.
Note / Clarification: All three of them (Ma'mar, al-Khuraybi and Ibn Abi al-Zinad) narrate it from Hisham bin 'Urwah, from his father, as mursal. In Ma'mar's narration it is made explicit that the sentence "that makes it smell bad" is Hisham bin 'Urwah's own words.