As for al-Ḥakam ibn Ṭuḥmān—he is Ibn Abī al-Qāsim. In al-Taʿjīl it is stated:
“Abū Zurʿah said, ‘A trustworthy shaykh, a righteous man,’ while Abū Ḥātim said, ‘There is no objection to him; his ḥadith are acceptable.’ Ibn Ḥibbān, however, deemed him weak in the Dhayl. I add: Ibn Maʿīn also declared him reliable.”

Tenth report: Abū Thaʿlabah al-Khushani said:
“I campaigned with the Messenger of Allah ﷺ at Khaybar while the people were hungry… (full report). He continued: We found onions and garlic in its orchards while the people were hungry, so they ate until they were satisfied. When they returned, the mosque reeked of onions and garlic, whereupon the Messenger of Allah ﷺ said, ‘Whoever has eaten from this noxious plant must not come near us…’ (to the end of the ḥadith).”

Ahmad transmitted it through the chain: Baqiyyah → Buḥayr ibn Saʿd → Khālid ibn Maʿdān → Jubayr ibn Nufayr → Abū Thaʿlabah.

All the transmitters in this isnād are reliable, except that Baqiyyah practiced tadlīs and here he reports with an unqualified “ʿan.”

Concerning this ḥadith, al-Mundhirī—followed by al-Haythamī—said:
“Al-Ṭabarānī narrated it in al-Kabīr with a ḥasan chain.”

I remark: First, the report is found in the Musnad and should have been attributed to it. Second, the presence of an ʿanʿanah from a mudallis conflicts with grading it ḥasan; perhaps Baqiyyah gave an explicit statement of audition in al-Ṭabarānī’s version.

These aḥādīth, then, contain an emphatic prohibition barring anyone who has eaten garlic or the like from entering