Surah 8

Surah 8:72

"Surely those who have believed and emigrated, and struggled with their wealth and their lives in the way of God, and those who have given refuge and help, those – they are allies of each other. But those who have believed and not emigrated – their protection is not (an obligation) on you at all, until they emigrate. Yet if they seek your help in the (matter of) religion, (their) help is (an obligation) on you, unless (it be) against a people with whom you have a treaty. God sees what you do."

8.72 – Surely those who have believed and emigrated, and struggled with their wealth and their lives in the way of God
The closing verses of this sūra provide a good opportunity to enquire into the meaning of jihad in the Quran.
The Arabic verb at the root of the term, jāhada , appears in verses 72, 74, and 75. The verb is here translated “struggled,” but what kind of struggle is meant? The context of this sūra is about fighting (vv. 39, 65), taking captives (v. 70), and dividing up the spoils (vv. 1, 41, 69). In such a context, it is reasonable to understand the “struggling” as physical, military, and armed.
The classical Muslim commentator al-Ṭabarī (d. 923) consistently interpreted jihād and jāhada to mean fighting, even when the context is not as suggestive as in the eighth sūra.

- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam