سنن النسائي

It was narrated from Muhammad bin 'Abdullah bin Al-Harith bin Nawfal bin Al-Harith bin 'Abdul-Muttalib that: during the year that Mu'awiyah bin abi sufyan performed Hajj, he heard Sa'd bin Abi Waqqas and Ad-Dahhak bin Qais talking about joining 'Umrah to Hajj (Tamattu) Ad-Dahhak said: "none does that but one who is ignorant of the ruling of Allah." Sa'd said: "What a bad thing to say, O son of my brother!" Ad-Dahhak said: "Umar bin Al-Khattab forbade that." Sa'd daid: "The Messenger of Allah (ﷺ) did that and we did it with him."