Praise be to Allah,
Ismaa’eel ibn Ibraaheem narrated to us from ‘Abdul-‘Azeez ibn Shuhayb from Anas ibn Maalik who said,
“Allah’s Messenger (PBUH) said, ‘Whoever wears silk in this world will not wear it in the hereafter.”‘
(Musnad Ahmad, Vol. 3, p. 101. The isnaad of this hadeeth is Saheeh according to the conditions set by al-Bukhaaree and Muslim)
Note: The Prophet (PBUH) was addressing men as it is allowed for women to wear silk.
Source:
Thulaathiyyaat Musnad Ahmad ibn Hanbal (may Allah have mercy on him)
Reports of Imaam Ahmad that have only three narrators between him and the Prophet, peace, and blessings be upon him.
Shaykh Muhammad ibn Ahmad ibn Saalim as–Saffaareenee al–Hanbalee ~(1114 –1188 AH)