﴿ بَلْ ظَنَنتُمْ أَن لَّن يَنقَلِبَ ٱلرَّسُولُ وَٱلْمُؤْمِنُونَ إِلَىٰٓ أَهْلِيهِمْ أَبَدًۭا وَزُيِّنَ ذَٰلِكَ فِى قُلُوبِكُمْ وَظَنَنتُمْ ظَنَّ ٱلسَّوْءِ وَكُنتُمْ قَوْمًۢا بُورًۭا ﴾

“Nay, you thought that the Apostle and the believers would never return to their kith and kin: and this seemed goodly to your hearts. And you entertained [such] evil thoughts because you have always been people devoid of all good!””

Please check ayah 48:14 for complete tafsir.