To understand what was in his brothers ’ hearts, Joseph concealed his identity when they appeared before him in Egypt to buy food.
وَعِنْدَمَا تَأَثَّرَ كَثِيرًا وَشَعَرَ بِحَاجَةٍ إِلَى ٱلْبُكَاءِ ،‏ ٱنْسَحَبَ لِيُخْفِيَ دُمُوعَهُ عَنْهُمْ .‏