It is narrated from Sayyiduna Zayd bin Khalid al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever equips a fighter will have a reward equal to his, and whoever looks after the family of a fighter in his absence will also have a reward equal to his."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5214