Notice, rather than leaving all physical possessions behind like those pioneers needed to do to lighten their load, God provided much more physically for their journey. They added great material possessions from the spoils of Egypt before their journey out began with setting sun that started the 15th day, and the first day of Unleavened Bread.
Notice it says in verse 35 that they had done all this at the word of Moses.
That is in there to show you and me they were doing something that they ordinarily would not have done. But God pushed the button in their mind, and made them (the Egyptians) give of their wealth freely.
Why the translators used the word "borrowed" here I have no idea. The Egyptians owed them that money for all the work they had done as slaves.
