Question: A question came in regards to mentioning this supplication in the storefronts, or groceries, or supermarket. Is it sufficient to mention [the supplication of the market] in the markets of our custom nowadays or is for the general market?
Answer: “In any case, if a person says it in a place of buying and selling, even in a specific market, and he says: Lā ilāha illallāh, waḥdahu lā sharīka lahu, no doubt this is what is necessary for a person to do because the first affair is easy. If he goes to a place of buying and selling, whether a specific market or general market [he says the supplication]”.
[Sharh Sunan Tirmidhi no. 378]
Faisal Ibn Abdul Qaadir Ibn Hassan