Musnad Ahmad 962:151

Abu al-Mughirah narrated to us, Ma'an ibn Rifa'ah narrated to us, 'Ali ibn Yazid narrated to me, from al-Qasim Abu 'Abd al-Rahman, from Abu Umamah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) was sitting in the mosque, and they used to think that revelation was descending upon him, so they refrained from approaching him. Then Abu Dharr came and pushed through, and he came and sat with him. The Prophet (peace and blessings of Allah be upon him) turned to him and said: "O Abu Dharr, have you prayed today?" He said: "No." He said: "Stand and pray." When he had prayed four rak'ahs of Duha, he turned to him and said: "O Abu Dharr, seek refuge in Allah from the evil of the devils of jinn and mankind." He said: "O Prophet of Allah, are there devils among mankind?" He said: "Yes, the devils of mankind and jinn inspire one another with decorative speech as a deception." Then he said: "O Abu Dharr, shall I not teach you a word from the treasure of Paradise?" He said: "Yes, may Allah make me your ransom." He said: "Say: *La hawla wa la quwwata illa billah* (There is no power and no strength except by Allah)." He said: So I said: *La hawla wa la quwwata illa billah*. He said: Then he remained silent toward me, and I found his speech slow in coming. I said: "O Prophet of Allah, we were a people of ignorance and idol worship, then Allah sent you as a mercy to the worlds. What do you say about prayer, what is it?" He said: "The best subject; whoever wishes may do little, and whoever wishes may do much." I said: "O Prophet of Allah, what do you say about fasting, what is it?" He said: "A duty that is rewarded." I said: "O Prophet of Allah, what do you say about charity, what is it?" He said: "Multiplied many times over, and with Allah is the increase." I said: "O Prophet of Allah, which charity is best?" He said: "Secretly to a poor person, and the effort of one who has little." I said: "O Prophet of Allah, which of what was revealed to you is the greatest?" He said: "{Allah - there is no deity except Him, the Ever-Living, the Sustainer of [all] existence} [Al-Baqarah: 255], the Verse of the Throne." I said: "O Prophet of Allah, which martyrs are the best?" He said: "He whose blood is shed and whose horse is hamstrung." I said: "O Prophet of Allah, which slaves are best [to free]?" He said: "The most expensive of them in price and the most precious of them to their owners." I said: "O Prophet of Allah, which of the prophets was the first?" He said: "Adam." I said: "O Prophet of Allah, was Adam a prophet?" He said: "Yes, a prophet spoken to. Allah created him with His hand, then He breathed into him of His spirit, then He said to him: 'O Adam, face to face.'" I said: "O Messenger of Allah, how many were the number of the prophets?" He said: "One hundred and twenty-four thousand. The messengers among them were three hundred and fifteen, a large group."