Al-Matalib al-'Aliyah 4313 — The Battle of Tabuk

It is narrated from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that we set out with the Messenger of Allah (peace and blessings be upon him) (on a journey), until, when we reached the place called Ayn al-Rum, and this was the expedition of Tabuk, we were struck by severe hunger. I said: "O Messenger of Allah! Tomorrow we will meet the enemy; they are well fed and full, while we are hungry (so how will we fight?)." At this the Prophet (peace and blessings be upon him) addressed the people and then said: "Whoever has surplus food, let him bring it to us." Then he (peace and blessings be upon him) spread out a leather mat, and a little over twenty sa' of grain were brought and placed on it. Then the Messenger of Allah (peace and blessings be upon him) sat down and supplicated for blessing, then he called the people and said: "Take (from it)." The people began to take, until things reached the point where a man would tie up the sleeve of his shirt (at the bottom) and fill it with grain, and even so some food was left over. Then the Messenger of Allah (peace and blessings be upon him) said: "I bear witness that there is no true god but Allah and that I am the Messenger of Allah. Whoever says these words sincerely and truthfully will never enter the Fire."
The chain of this hadith contains Yazid bin Abi Ziyad and Asim bin Ubaydullah, who are da'if (weak) narrators. However, other supporting evidence for the miracle of the multiplication of food and the virtue of the testimony of faith exists in sahih hadith.