Quran (2:216) – "Allah Knows And You Don't Know"
Allah knows the result that a particular action will accrue both in this world and in the hereafter which has an ethical basis. We humans often knowing the moral soundness of an action still get into a dilemma because of our prejudice, emotions, whims and wsihes. Our judgement may become clouded, but Allah knows the ultimate result of a sound ethical action. Similar circumstances were faced at that time by the people to whom this verse is addressing. Fighting with Quraish at that time had its clear moral basis, but the war itself and then fighting one’s own kindred in the war were standing in conflict to what was morally understood in the context (i.e. the war ). And people who didn’t have a strong faith were compelled to some extent to ask these questions regarding ‘ Infaq ‘ and ‘ Jihad ‘, and some were of view that maybe at that time war could’ve been avoided to protect their family members and in time, their family members might accept faith. Please also refer to the video below from 16:40 to 20:02 https://youtu.be/G8y1BjIX5Hk?t=1000