202 – On the authority of Abu Hurayrah (may Allah be pleased with him), the Messenger of Allah (peace and blessings be upon him) said: “If you see someone selling or buying inside the mosque, say to him, ‘May Allah not make your trade profitable.’” Reported by al-Nasāʾī and al-Tirmidhī, who classed it as fair. (1)

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Authenticity of the ḥadith
This ḥadith is authentic. Al-Tirmidhī said, “It is a fair, singular report.” Al-Suyūṭī declared it authentic in al-Jāmiʿ al-Ṣaghīr. Al-Ḥākim also authenticated it (2/65) and al-Dhahabī agreed with him. Al-Albānī stated, “Its chain is authentic according to Muslim’s criteria.”

Vocabulary
• “or yabtāʿ” (or buys): derived from bāʿ, the span between the two hands when they are stretched right and left. Because the parties to a sale extend their arms when transacting, the verb bāʿa (to sell) was coined, and ibtāʿa came to mean “to purchase.”
• “tijāratak” (your trade): a verbal noun that came to denote the occupation of buying and selling.
• “lā arbaḥa Allāhu tijārātak” (may Allah not grant your trade profit): i.e., may He not make it successful or beneficial.

Points derived from the ḥadith
1 – The apparent purport of the ḥadith is that whoever hears someone selling or buying in the mosque must say to him aloud, “May Allah not make your trade profitable,” for mosques were not built for commerce.
2 – Buying and selling in the mosque are prohibited. As for whether the contract is nonetheless valid despite the prohibition, Imām al-Shāfiʿī and many other scholars maintain that it is valid, though sinful.