Please provide the original source, and comment on the authenticity of this narration.
Sulaym ibn ‘Aamir narrates that when winter would come, Sayyiduna ‘Umar (radiyallahu ‘anhu) would be extra mindful of them and write to them, advising:
“Winter, which is an enemy, has come, so prepare for it with wool, leathers socks, and socks. Use wool as your under-clothing and outer-clothing, because the cold is an enemy that enters quickly but leaves slowly.”
Imam ‘Abdullah ibnul Mubarak (rahimahullah) has recorded this from reliable narrators.
(Refer: Lataiful Ma’arif, pg.564)
Hafiz Ibn Rajab (rahimahullah) writes:
‘This was part of Sayyiduna ‘Umar’s (radiyallahu’anhu) well wishing, compassion and good regard for his subjects.’
(Lataiful Ma’arif, pg.564)
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And Allah Ta’ala Knows best,
Answered by: Moulana Muhammad Abasoomar