That the Messenger of Allah (ﷺ) said: "Wearing silk and gold has made unlawful for the males of my Ummah and lawful for its females.

There are narrations on this topic from 'Umar, 'Ali, 'Uqbah bin 'Amir, Anas, Umm Hani, Hudhaifah, 'Abdullah bin 'Amr, 'Imran bin Husain, 'Abdullah bin Az-Zubair, Jabir, Abu Raihanah, Ibn 'Umar, Al-Bara', and Wathilah bin Al-Asqa', and this Hadith is Hasan Sahih.
Jami` at-Tirmidhi Book 24, Hadith 1
← Previous Hadith "The wealth of Banu An-Nadir was among the spoils of war which Allah granted upon His Messenger (ﷺ) which the Muslims did not gain with the rush of their horses nor camel. So it was purely for the Messenger of Allah (ﷺ), and the Messenger of Allah (ﷺ) would set aside a year's worth of expenditure for his family, then he would use what remained of it for horses and weapons to be used in Allah's cause."

This Hadith is Hasan Sahih. Sufyan bin 'Uyainah reported this Hadith from Ma'mar, from Ibn Shihab.

Jami` at-Tirmidhi Book 23, Hadith 53 Next Hadith → That 'Umar gave a Khutbah at Al-Jabiyah and he said: "The Messenger of Allah (ﷺ) prohibited silk except for two finger's worth of space, or three, or four."

This Hadith is Hasan Sahih.

Jami` at-Tirmidhi Book 24, Hadith 2