According to Shahristani's fourth Introduction to his book Al-Milal wal Nihal ...

According to Shahristani's fourth Introduction to his book Al-Milal wal Nihal , the Prophet (pbuh) is quoted saying: "Draft in Usamah's army; may Allah curse its draft dodgers." You may also know that initially they were reluctant to go with the regiment; then they finally dodged, just to firmly lay the foundations of their political structure and set its bases, preferring it to the carrying out of the orders of the Prophet.

They saw that such a political structure was more worthy of their concern and attention, since…