Moshe said to Chovav, the son of Reuel the Midyani, Moshe’s father-in-law, "We are journeying to the place of which Hashem said, 'I will give it to you.' Come with us, and we will treat you well; for Hashem has spoken good concerning Israel."
The Ohr Hachaim asks why they had to tell Chovav that they were journeying to the place that Hashem had promised them. Did he not know that they were on their way somewhere? What did this sentence add to the conversation?
The Sifrei explains that they were telling Chovav that this was their final trip before arriving at the promised land. They were not making any other steps along the way.
The possuk also says אֹתוֹ אֶתֵּן לָכֶם - I will give it to you. The land is already mentioned in the possuk, the Torah could have said נֹסְעִים אֲנַׂחְנוּ אֶל הַׂמָקוֹם אֲשֶר אָמַׂר ה' אֶתֵּן לָכֶם.
The Ohr Hachaim explains that Hashem did not promise us more than the land of Canaan, He did not promise us the land of Sichon and Og. They were then on the way to the land of Sichon through which they would enter Eretz Yisroel. Seeing as they were not due to inherit this land, but they were going to conquer it as a nation, and Hashem was about to give it to them. That is the meaning of the possuk that they were traveling immediately to the place that Hashem had said He would give you, not their forefathers. They knew, through prophecy, that this would happen and they would conquer the lands of Sichon and Og.
It is possible the Ohr Hachaim means to say that at the time, the lands of Sichon and Og were not due to any of Klal Yisroel, and they were offering it to the children of Chovav.
