Yahya related to me from Malik from Humayd ibn Qays from Ata ibn Rabah that a bedouin came to the Messenger of Allah ﷺ when he was at Hunayn, and he was wearing a shirt with traces of yellow on it. He said, "Messenger of Allah, I have entered ihram for umra. What should I do?" The Messenger of Allah ﷺ said to him, "Take off your shirt and wash off this yellowness and do in umra as you would do on hajj."
أَنَّ أَعْرَابِيًّا جَاءَ إِلَى رَسُولِ اللَّهِ ﷺ وَهُوَ بِحُنَيْنٍ وَعَلَى الأَعْرَابِيِّ قَمِيصٌ وَبِهِ أَثَرُ صُفْرَةٍ فَقَالَ يَا رَسُولَ اللَّهِ إِنِّي أَهْلَلْتُ بِعُمْرَةٍ فَكَيْفَ تَأْمُرُنِي أَنْ أَصْنَعَ فَقَالَ لَهُ رَسُولُ اللَّهِ ﷺ انْزِعْ قَمِيصَكَ وَاغْسِلْ هَذِهِ الصُّفْرَةَ عَنْكَ وَافْعَلْ فِي عُمْرَتِكَ مَا تَفْعَلُ فِي حَجِّكَ