Abu Hurairah reported,
The Prophet ﷺ said, "There are three whom Allah 
has taken it upon Himself to help. The one who fights in the path of Allah , the one who marries seeking chastity, and the slave under a contract of manumission who intends to pay it off."
Ahmad 9631
Sahihحدثنا يحيى عن ابن عجلان قال حدثني سعيد
عن أبي هريرة
عن النبي ﷺ قال ثلاثة كلهم حق على الله عز وجل عونه المجاهد في سبيل الله عز وجل والناكح ليستعفف والمكاتب يريد الأداء
Its chain of transmission is sahih. Tirmidhi 4/184 no. 1655 narrated it in the chapters on the merits of jihad, in what has been reported about the one who fights jihad and the one who marries, and graded it hasan. Nasai 6/16 no. 3120 narrated it in the book of jihad, as did Ibn Majah 2/841 no. 2518, and Hakim 2/160, who graded it sahih, and Dhahabi agreed with him.