If you happen to think to yourself, These nations are greater than we are; how can we possibly possess their land?
If thou shalt say in thine heart, These nations are more than I; how can I dispossess them?
If you say in your [minds and] hearts, These nations are greater than we are; how can we dispossess them?
If thou shalt say in thy heart, These nations are more than I; how can I dispossess them?
If you say in your heart, 'These nations are more than I am, so how will I be able to destroy them?'
If thou say in thy heart: These nations are more than I, how shall I be able to destroy them?