Umar bin Khattab reported,
I heard the Messenger of Allah ﷺ say, "Whoever equips a warrior in the path of Allah until he sets out fully prepared will have a reward equal to his, until the warrior dies or returns."
Ibn Majah 2758
Sahihحدثنا أبو بكر بن أبي شيبة حدثنا يونس بن محمد حدثنا ليث بن سعد عن يزيد بن عبد الله بن الهاد عن الوليد بن أبي الوليد عن عثمان بن عبد الله بن سراقة
عن عمر بن الخطاب قال
سمعت رسول الله ﷺ يقول من جهز غازيا في سبيل الله حتى يستقل كان له مثل أجره حتى يموت أو يرجع
Takhrij, [sahih] Ahmad narrated it, 1/20, from Yunus and others through him. It is also found in Musannaf of Ibn Abu Shayba, 5/351. Ibn Hibban graded it sahih (Mawarid), no. 1654, as did Hakim, 2/89, and Dhahabi.I say, Walid bin Abu Walid is trustworthy. Abu Zura, Ajli, Ibn Shahin, Ibn Hibban, Dhahabi in Kashif, and others deemed him trustworthy. Uthman explicitly stated that he heard it from his maternal grandfather, Umar 
, according to Tabari in Tahzib Athar, though Ibn Madini and others denied this. The hadith has many corroborating narrations, see the following hadith.