Does the hadith "I was enrolled in the expedition of such-and-such" indicate that they used to write down the names of the expedition participants?

Question:
Honorable Shaykh, may Allah grant you success. In the hadith , does this not indicate that they used to write down the names of the expedition participants during the time of the Messenger (peace and blessings be upon him)?

Answer:
If they wrote them down but did not have salaries, that was only in the time of 'Umar ibn al-Khattab, when they wrote them down and gave them salaries from the public treasury.