Abu Salih (may Allah have mercy on him), regarding the saying of Allah Almighty: "If you know any good in them" [Surah al-Nur: 33], says that what is meant by it is paying (what is due) and trustworthiness. [Da'if]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المكاتب / 21610