Hashem promised protection for the property of the travellers to Jerusalem while they were gone: Pesachim 8b
Hashem didn't put "Peirot Ginosar" [extra-sweet fruit] or Hot Springs in Jerusalem, so that they would ascend to Jerusalem for Pure Motives: Pesachim 8b
Hashem's anger when the Jews came to celebrate holidays in sinfulness: Shabbat 145b
