Imam Ali (peace be upon him): Imam Sadiq (peace be upon him) narrates from Imam Ali (peace be upon him) who said: When the Messenger of Allah (peace be upon him and his family) set out toward Badr in pursuit of the enemy, he said to his companions: "Allah, the Mighty and Majestic, has promised me that I will prevail over either the trade caravan or [the army of] Quraysh." So the companions set out with the Messenger of Allah (peace be upon him and his family) on the basis of this promise. When the trade caravan slipped out of reach and Allah commanded the Prophet (peace be upon him and his family) to fight Quraysh, he (peace be upon him and his family) said to his companions: "[The army of] Quraysh has drawn near, and Allah the Glorified has promised me that one of the two parties shall be yours [and you shall prevail over it], and He has commanded me to fight Quraysh." On hearing these words the companions became distressed and said: "O Messenger of Allah (peace be upon him and his family)! We did not come out with the readiness [and equipment] for war." And some of them engaged in much argument and dispute; at that point Allah the Exalted revealed this verse: وَ إِذْ یَعِدُکُمُ اللهُ إِحْدَى الطَّائِفَتَیْنِ أَنَّها لَکُمْ وَ تَوَدُّونَ أَنَّ غَیْرَ ذاتِ الشَّوْکَةِ تَکُونُ لَکُمْ وَ یُریدُ اللهُ أَنْ یُحِقَّ الْحَقَّ بِکَلِماتِهِ وَ یَقْطَعَ دابِرَ الْکافِرین [And when Allah promised you one of the two parties that it shall be yours, and you loved that the one not armed should be yours, and Allah desired to manifest the truth of what was true by His words and to cut off the root of the unbelievers].