Ata' bin Yasar reports the following statement of a Companion: Once a man was praying with his lower garment hanging down. The Prophet (peace and blessings be upon him) said to him: Go and perform ablution! The narrator says: The man went, and when he came back, the Prophet (peace and blessings be upon him) said: Go and perform ablution! Then the man came back, and he (that is, the narrating Companion) submitted: O Messenger of Allah! Why is it that you ordered this man to perform ablution and then remained silent about him? The Prophet (peace and blessings be upon him) said: "This man was praying with his lower garment hanging down, and Allah Almighty does not accept the prayer of a servant who lets his lower garment hang down."
The author of "al-Atraf" attributed this narration to Imam al-Nasa'i (may Allah have mercy on him); I did not find this narration in the copy I have; perhaps it is in "al-Sunan al-Kubra" of al-Nasa'i.
Ahmad recorded it, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب اللباس / 8531
Hadith Gradingمحدثین:إسنادہ صحیح۔
Hadith Takhrij«اخرجه احمد فى المسند (67/4) ، أخرجه سنن أبي داود برقم: 638، وأخرجه مسند أحمد برقم: 16192، 22706، وأخرجه البحر الزخار المعروف بمسند البزار 10 - 18 برقم: 8762»