Or HaChaim on Genesis 29:1/אור החיים על בראשית כ״ט:א׳

1 וישא יעקב רגליו. Jacob raised his feet. The Torah chooses this form of expression to tell us that at this time Jacob was poor and all he could raise [elevate to the status of tithes as promised in his vow, Ed.] were his feet. In the future he would tithe all his produce twice, i.e. give a total of 20% in order to fulfil the words עשר אעשרנו. The second tithe would not merely be 10% of what remained after the first tithe had been given (compare Ketuvot 50).

2An additional meaning of the Torah's description of Jacob "raising his feet" is that he did not actually have to walk the entire distance to Charan but that the land came toward him. This is the reason the Torah did not say אל ארץ בני קדם, "to the land of the easterners, but ארצה בני קדם."

3The reason the Torah describes these people as בני קדם, easterners, instead of referring to their city, i.e. Charan, is to tell us that only the district came towards him. Jacob himself walked to Charan in order to find there his Rachel and in order for him to obtain from her all the information she furnished him as described in Megillah 13.