Hadith: The best dinar a man spends is a dinar that he spends on his dependents, and a dinar that a man spends on his mount in the cause of Allah, and a dinar that he spends on his companions in the cause of Allah

عَنْ ثَوْبَانَ رضي الله عنه قَالَ: قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ:
«أَفْضَلُ دِينَارٍ يُنْفِقُهُ الرَّجُلُ، دِينَارٌ يُنْفِقُهُ عَلَى عِيَالِهِ، وَدِينَارٌ يُنْفِقُهُ الرَّجُلُ عَلَى دَابَّتِهِ فِي سَبِيلِ اللهِ، وَدِينَارٌ يُنْفِقُهُ عَلَى أَصْحَابِهِ فِي سَبِيلِ اللهِ» قَالَ أَبُو قِلَابَةَ: وَبَدَأَ بِالْعِيَالِ، ثُمَّ قَالَ أَبُو قِلَابَةَ: وَأَيُّ رَجُلٍ أَعْظَمُ أَجْرًا مِنْ رَجُلٍ يُنْفِقُ عَلَى عِيَالٍ صِغَارٍ، يُعِفُّهُمْ أَوْ يَنْفَعُهُمُ اللهُ بِهِ وَيُغْنِيهِمْ.
[صحيح] - [رواه مسلم] - [صحيح مسلم: 994]

Thawbān (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said:
"The best dinar a man spends is a dinar that he spends on his dependents, and a dinar that a man spends on his mount in the cause of Allah, and a dinar that he spends on his companions in the cause of Allah." Abu Qilābah said: He began with the dependents. Then Abu Qilābah said: No man is greater in reward than a man who spends on young dependents, by virtue of whom Allah makes them chaste, or brings them benefit and enriches them.
[Authentic hadith] - [Narrated by Muslim] - [Sahih Muslim - 994]

Explanation

The Prophet (may Allah's peace and blessings be upon him) clarified some forms of spending and put them in order according to the most obligatory ones in case numerous channels of spending crowd together, starting with the most important and then the next in importance. He stated that the money that brings one the highest reward for spending is the money that a Muslim spends on his dependents, like his wife and children, followed by spending on the mount that is prepared for war in the cause of Allah, then spending on one's friends and companions if they are fighters in the cause of Allah.