Sayyiduna Zayd bin Khalid al-Juhani (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever equips a fighter has, as it were, fought himself; and whoever looks after the family of a fighter in his absence with goodness has also, as it were, fought himself."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5210