مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1545
Musnad Abu Ishaq Sa'd bin Abi Waqqas
It was narrated fromʻAmir bin Sa"d, from his father, who attributed it to the Prophet (ﷺ) : “The Muslim who causes the greatest offence against the Muslims is the one who asks about something that was not forbidden, then it became forbidden for the people because of his asking"
Musnad Ahmad 1545Sahih (Darussalam) [ al-Bukhari (7289) and Muslim (2358)]