"When the Messenger of Allah , I will fight them for it.' 'Umar said: 'By Allah, as soon as I realized how certain Abu Bakr was, I knew that it was the truth.'"
Sunan an-Nasa'i Book 37, Hadith 4
← Previous Hadith "O Abu Hamzah, what makes the blood and wealth of a Muslim forbidden?" He said: "Whoever bears witness to La ilaha illallah (there is none worthy of worship except Allah) and that Muhammad is the Messenger of Allah , faces our Qiblah, prays as we pray, and eats our slaughtered animals, he is a Muslim, and has the same rights and obligations as the Muslims."

Sunan an-Nasa'i Book 37, Hadith 3 Next Hadith → "When the Messenger of Allah , I will fight them for withholding it.' 'Umar, may Allah be pleased with him, said: 'By Allah, as soon as I realized that Allah has expanded the chest of Abu Bakr for fighting, I knew that it was the truth.'"

Sunan an-Nasa'i Book 37, Hadith 5