Musnad Ahmad 1065:15

Yunus narrated to us, Laith narrated to us, from Yazid, from Amr, the freed slave of Al-Muttalib, from Asim ibn Umar ibn Qatadah, from Mahmud ibn Labid, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "If Allah loves a people, He tries them. So whoever is patient, for him is patience, and whoever is impatient, for him is impatience."