The Emigrants had left Mecca with almost nothing. The Qur'an says it: driven from their homes and their wealth.
Ibn 'Abbâs tells it: when the Prophet ﷺ was driven out of Mecca, Abû Bakr said: they have expelled their prophet.
Permission is given to those who are fought, because they were wronged. And Allah is well able to give them victory.
Abû Bakr (may Allah be pleased with him) said: then I knew that there would be fighting.
The Prophet ﷺ heard that Abû Sufyân was coming back from Shâm with a great caravan, thirty or forty men with it.
He called the people out to it: perhaps Allah would grant it to them. Some came quickly, some not.
Those who stayed behind had a reason: no one thought the Messenger of Allah ﷺ was going to meet a war.
Anas (may Allah be pleased with him) tells it: the Prophet ﷺ sent Busaysa as a scout, to see what the caravan was doing.
When he came back, the Prophet ﷺ went out and said: we have an errand; whoever has his mount ready, ride with us.
Men asked to fetch mounts grazing above Medina. He said no: only those whose mount was at hand. They left as they were.
So Badr began without an army made ready: a few hundred men, on whatever mounts were at hand.
They had seventy camels between them and rode by turns. He ﷺ shared one with 'Alî and Marthad, like everyone else.
The biographers tell it: Abû Sufyân learned of the march and sent a rider to Mecca, calling Quraysh to their goods.
Almost every clan sent men. Abû Lahab stayed home, and sent in his place a man who owed him money.
Umayya ibn Khalaf did not want to go. His friend Sa'd ibn Mu'âdh had told him: the Prophet ﷺ says they will kill you.
He had sworn not to leave Mecca. Abû Jahl pressed him until he gave in, meaning to turn back soon. He never did.
Quraysh set out. Abû Sufyân, meanwhile, turned his caravan towards the coast and slipped away from Badr.
He then sent word to Quraysh: your caravan is safe, go back. Abû Jahl refused to turn back before reaching Badr.
He wanted three days of feasting there, so that all the Arabs would hear of their march and fear them for ever.
The men of Banû Zuhra saw it differently: their goods were safe. They went home, and not one of them was at Badr.
Do not be like those who came out of their homes boastfully, to be seen by people, barring the way of Allah.
Two crowds left their homes that month. One had been driven out of them. The other marched out to be seen.
So the caravan was gone. Ahead of the few hundred men who had come out for it, there was now an army.
In the second year after the Hijra, a caravan of Quraysh passed near Medina. No one set out for a war.
How did a march towards a caravan become the day the Qur'an calls the criterion?
A people driven from their homes, a caravan that slipped away, and an army that came out to be seen.
Tonight, take one thing you plan for tomorrow, and ask yourself whom you are doing it for.