Al-Tirmidhi HadithHadith 4795 Narrated byKa'b ibn Malik
Ka'b said to the Prophet (peace be upon him), "Allah has sent down concerning poetry what He has sent down." The Prophet (peace be upon him) replied, "The believer strives with his sword and his tongue. By Him in Whose hand my soul is, it is as though you are shooting at them with it like the spraying of arrows."
It is transmitted in Sharh as-Sunnah. In al-Isti'ab by Ibn AbdulBarr Ka'b said, "Messenger of Allah, what is your opinion about poetry?" and he replied,
"The believer strives with his sword and his tongue."
Sahih Al-Bukhari HadithHadith 4.266A Narrated bySalim Abu An Nadr
(the freed slave of 'Umar bin 'Ubaidullah) I was Umar's clerk. Once Abdullah bin Abi Aufa wrote a letter to 'Umar when he proceeded to Al-Haruriya. I read in it that Allah's Apostle in one of his military expeditions against the enemy, waited till the sun declined and then he got up amongst the people saying, "O people! Do not wish to meet the enemy, and ask Allah for safety, but when you face the enemy, be patient, and remember that Paradise is under the shades of swords." Then he said, "O Allah, the Revealer of the Holy Book, and the Mover of the clouds and the Defeater of the clans, defeat them, and grant us victory over them."
*** There are of course HUNDREDS more of such verses for those who want more details ***