Qur'an 9:42

لَوْ كَانَ عَرَضًا قَرِيبًا وَسَفَرًا قَاصِدًا لَّٱتَّبَعُوكَ وَلَـٰكِنۢ بَعُدَتْ عَلَيْهِمُ ٱلشُّقَّةُ ۚ وَسَيَحْلِفُونَ بِٱللَّهِ لَوِ ٱسْتَطَعْنَا لَخَرَجْنَا مَعَكُمْ يُهْلِكُونَ أَنفُسَهُمْ وَٱللَّهُ يَعْلَمُ إِنَّهُمْ لَكَـٰذِبُونَ

“Had it been a near [i.e., easy] gain and a moderate trip, they [i.e., the hypocrites] would have followed you, but distant to them was the journey. And they will swear by Allāh, "If we were able, we would have gone forth with you," destroying themselves [through false oaths], and Allāh knows that indeed they are liars.”

At-Tawba 9:42 · Saheeh International