Ibn Abi al-Dunyaa relates through Shihr bin Hawshab:

Abd al-Rahmaan bin Mu'adh bin Jabal (rahimahullaah) was afflicted with the plague. His father entered upon him and said, "How do I find you my dear son?" He replied (with the saying of Allaah), "The truth is from your Lord. So be not of those who doubt" (2:147). So Mu'adh said to him (responding with the saying of Allaah), "You will find me, if Allaah wills, from those who patiently persevere" (37:102).

Note: This indicates belief in al-qadr (divine decree) and what follows from it of sabr (patience).

In Mawsoo'ah Ibn Abi al-Dunyaa (5/341) through Hayat al-Salaf of Ahmad al-Tayyar.
Translated by Abu Iyaad (@abuiyaadsp)