Mishkat al-Masabih 19 Jihad كتاب الجهاد 39

وَعَنْ أَبِي أُمَامَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَفْضَلُ الصَّدَقَاتِ ظِلُّ فُسْطَاطٍ فِي سَبِيلِ اللَّهِ وَمِنْحَةُ خَادِمٍ فِي سَبِيلِ اللَّهِ أَوْ طَرُوقَةُ فَحْلٍ فِي سَبِيلِ اللَّهِ» . رَوَاهُ التِّرْمِذِيُّ

Abu Umama reported God’s Messenger as saying, “The best sadaqat are the shade of a large tent in God’s path, the gift of a servant in God’s path, or providing in God’s path a she-camel old enough to be covered by a stallion.” Tirmidhi transmitted it.