جامع الترمذي

Narrated Abu Hurairah:

"It was said, 'O Messenger of Allah, what equals Jihad?' He said: 'Verily, you (people) are not capable of it.' So they repeated it to him two or three times, each time he said, 'You (people) are not capable of it.' Then he said the third time: 'The example of the Mujahid in the path of Allah is like the one who fasts and stands (in prayer) and does not slacken from Salat, nor fasting, until the Mujahid in the cause of Allah returns.'"

There are narrations on this topic from Ash-Shifa', 'Abdullah bin Hubshi, Abu Musa', Abu Sa'eed, Umm Malik Al-Bahziyyah, and Anas.

This Hadith is a Hasan Sahih. And it has been reported through more than one route from Abu Hurairah from the Prophet (ﷺ).