Testimony from a non-muslim about the Muslim conquest of Jerusalem that is contrary to the myth of Islam being spread by the sword!

A correction on one of his comments in the end:
Umar Ibn Al Khattab (RadiAllahu Anhu - may Allah be pleased with him) grounded Khalid Ibn Al Waleed (RadiAllahu Anhu - may Allah be pleased with him), not because he was under threat of losing out on popularity or that Khalid (R.A.) was a threat to the Khilafah. It was because the new muslims and foreign lands coming under Islamic rule started attributing special powers to Kahlid (R.A.) and developing the belief that the Muslims could not lose under Khalid's (R.A.) leadership. It was a higher priority for Umar (R.A) to demonstrate that victory comes from Allah and could be achieved in Khalid's (R.A.) absence as well. Umar (R.A.) also wanted to protect Khalid's title - Saifullah ( the sword of Allah) and did not want him to die in battle as this would mean that the sword had been defeated or broken, and it could be a huge psychological blow to the average muslim soldier who believed that Khalid (R.A.) was invincible.

This is borne out by the fact that despite being the Khalifah, Umar (R.A) did not surround himself with worldly luxuries or benefits and lived a very simple life