Muwatta Malik, Book 48, Hadith 3 (USC-MSA)

Yahya related to me from Malik from Ayyub ibn Abi Tamim that Ibn Sirin said, ''Umar ibn al-Khattab said, 'Allah has been generous to you, so be generous to yourselves. Let a man wear a combination of his garments.' "

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ أَيُّوبَ بْنِ أَبِي تَمِيمَةَ، عَنِ ابْنِ سِيرِينَ، قَالَ قَالَ عُمَرُ بْنُ الْخَطَّابِ إِذَا أَوْسَعَ اللَّهُ عَلَيْكُمْ فَأَوْسِعُوا عَلَى أَنْفُسِكُمْ جَمَعَ رَجُلٌ عَلَيْهِ ثِيَابَهُ ‏.‏

sunnah.com

also referenced under: Book 48, Hadith 1656 (In-Book)