Hadrat Umar and Qadar

We were covering Hikam 22 of Ibn 'Ata' Illah's famous Book of Wisdoms (al-Hikam al-'Ata'iyya) during Sh Zahir's Halaqa last week. The commentry of nthe hikam included the followiung incident related to Hadrat Umar and Qadar ( Decree):

Umar bin al-Khatab was travelling with a group of Sahabas during his Khalifah (leadership). They were coming to a town when they heard that it had a contagious/infectious disease i.e. cholera. Umer asked his group whether they should proceed or go back ( to Madinah). The majority of the Sahabahs said they should go back but some said they should proceed. Then one Sahabi said he knew a hadith where the Prophet, sallahu' alayhi wassalam said, "If you hear that this disease exists in a country, don't travel to that country." So Umar decided that they should go back. Another Sahabi ( it seems from the second group) asked him whether he was running away from a qadar. Umar replied that they are moving away form one qadar to another qadar.