There was a cloud that led the Jews through the desert. Whenever it rested upon the tabernacle, the Jews would stop traveling and whenever the cloud rose up again, the Jews would continue traveling. Some days the cloud would rest for a long period of time, and the Jews would have to wait for it to rise up again until they could continue journeying. After the unfaithfulness the Jews had shown with the golden calf as a replacement God at Mount Sinai, God was testing their faith everyday with the cloud. They also had Moses go before them as their leader who prayed for them and was blessed by God, so that nobody could stand in their way of reaching the promised land.