At-Tawbah 9:92

وَلَا عَلَى ٱلَّذِينَ إِذَا مَآ أَتَوۡكَ لِتَحۡمِلَهُمۡ قُلۡتَ لَآ أَجِدُ مَآ أَحۡمِلُكُمۡ عَلَيۡهِ تَوَلَّواْ وَّأَعۡيُنُهُمۡ تَفِيضُ مِنَ ٱلدَّمۡعِ حَزَنًا أَلَّا يَجِدُواْ مَا يُنفِقُونَ 92

Nor [is there blame] upon those who, when they came to you that you might give them mounts, you said, "I can find nothing for you to ride upon." They turned back while their eyes overflowed with tears out of grief that they could not find something to spend [for the cause of Allah]