´It was narrated that Khuraim bin Fatik said:` "The Messenger of Allah (ﷺ) said: 'Whoever spends in the cause of Allah, it will be recorded for him seven hundred fold.'"
Related hadith on this topic
Explanation & Benefits
Hafiz Muhammad Ameen
English translation:
The reward for a good deed being tenfold is an obligatory matter. Anything beyond this depends on the sincerity of the individual concerned. There are also some sincere people who receive a sevenfold reward. And that is not difficult for Allah.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 3188