﴿ وَلَوْ نَشَآءُ لَأَرَيْنَٰكَهُمْ فَلَعَرَفْتَهُم بِسِيمَٰهُمْ ۚ وَلَتَعْرِفَنَّهُمْ فِى لَحْنِ ٱلْقَوْلِ ۚ وَٱللَّهُ يَعْلَمُ أَعْمَٰلَكُمْ ﴾

“Now had We so willed, We could have shown them clearly to thee, so that thou wouldst know them for sure as by a visible mark: but [even so,] thou wilt most certainly recognize them by the tone of their voice. And God knows all that you do, [O men;]”

The hypocrite Muslims were jealous of their pious brethren in religion? The reason was that they felt that all progress made by Islam benefitted sincere Muslims, and this was very distressing to them. They used to wonder why they should sacrifice their lives and property in a campaign which enhanced the position of others, while conferring no greatness on them. The hypocrites hid these inner feelings in their outward behaviour. But this did not remain concealed from people of understanding. Their artificial tone revealed that their connection with Islam was that of outward show and was not in any sense heartfelt.