Qur'an 9:92

وَلَا عَلَى ٱلَّذِينَ إِذَا مَآ أَتَوْكَ لِتَحْمِلَهُمْ قُلْتَ لَآ أَجِدُ مَآ أَحْمِلُكُمْ عَلَيْهِ تَوَلَّوا۟ وَّأَعْيُنُهُمْ تَفِيضُ مِنَ ٱلدَّمْعِ حَزَنًا أَلَّا يَجِدُوا۟ مَا يُنفِقُونَ

Nor unto those whom, when they came to thee (asking) that thou shouldst mount them, thou didst tell: I cannot find whereon to mount you. They turned back with eyes flowing with tears, for sorrow that they could not find the means to spend.