426 – ʿUmar (may Allah be pleased with him) said: “The Messenger of Allah ﷺ forbade wearing silk except for a strip the width of two, three, or four fingers.” Agreed upon, and this is Muslim’s wording. (1)

427 – Anas (may Allah be pleased with him) reported that “the Prophet ﷺ granted ʿAbd al-Raḥmān ibn ʿAwf and al-Zubayr a concession to wear a silk shirt during a journey because of an itching condition that afflicted them.” Agreed upon. (2)

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Lexical notes
• al-qamīṣ (shirt): plural qumṣān, qumṣ (both with ḍammah on the first two letters); a garment tailored to the shape of the body, worn beneath the outer cloak.
• min ḥikkah (“because of itching”): here min is causative, indicating the reason. Ḥikkah (with kasrah on the ḥāʾ and a shaddah on the kāf) is a skin ailment that induces scratching, such as scabies.