Commentary for Numbers 32:15

להניחו, “he will again leave you;” the letter ח in this word was exchanged from the original letter ע; we have proof of this in verse 13 in the word ויניעם, “He made them wander.” The word להניחו in this verse means that failure of the tribes of Reuven and Gad to reconsider will extend the length of their whole generation in exile in the desert, which includes constantly having to move. If the two tribes were to decline to settle in the west bank, history would likely repeat itself, and another generation would not get to see the promised Land. There are commentators who understand the word להניחו, as “to abandon it;” this would be analogous to Psalms 119,121: בל תניחני לעושקי, “do not abandon me to those who would wrong me.”