Why did the Prophet pawn his shield with a Jew instead of with his wealthy Companions?

The Companions used to race to serve the Prophet (peace be upon him) and prioritize him over themselves. However, the Prophet (peace be upon him) did not declare his need to them, either to demonstrate the permissibility of dealing with Jews and disbelievers, or because he knew that his Companions did not have surplus food, or he feared they would not accept payment from him. The Prophet (peace be upon him) would spend what he had in obedience to Allah, and he might conceal his need from the Companions, preferring to endure hardships. Yet, the Companions would hasten to alleviate his need if they became aware of it, as Abu Talha, Jabir, and Abu Shuaib al-Ansari did. Allah Almighty described them with His words: "and prefer [them] over themselves, even if they are in [dire] poverty" and "merciful among themselves."