The way of tzaddikim; the way of the Torah[1]
ועתה שא-נא כליך תליך וקשתך וצא השדה וצודה לי ציד
Now, please carry your vessels, your sword[2], and your bow; go out to the field and capture me some game[3]
Once Yitzchak approached the age that his mother was when she passed, he felt it was time to settle his affairs[4]. He decided to give incredibly powerful berachos, blessings, to his favorite son Eisav. However, to get into the proper state of mind to give these blessings, Yitzchak wanted to have a meal made up of his favorite delicacies. Eisav was an expert trapper[5]. So before receiving these blessings, Yitzchak sent him on a hunting mission. He told Eisav to take his instruments with him and go. Rashi is bothered[6] that one doesn’t need to tell an expert hunter to take along his weapons, just like a plumber doesn’t need to be told to bring his wrench[7]. Therefore, he interprets[8] the command שא-נא, literally please carry, as השחזה, sharpen. Yitzchak was telling Eisav to sharpen his knives. Why? Yitzchak was worried that when Eisav did shechitah, ritual slaughter on the animals he catches, the knife might have a blemish which would go unnoticed. Slaughtering with this knife would render the food forbidden to eat[9].