Third, do not worry because you cannot add an inch to your life by worrying. Jesus said, “And which of you by being anxious can add a single hour to his span of life” (Matt. 6:27)? In the NKJV, it reads, “can add one cubit to his stature.” But in the NASB, it says—“can add a single cubit to his life’s span.” In the ESV, it reads—“can add a single hour to his span of life.”
The word, “cubit” (NKJV) is from the Greek, pechus, “cubit, a measure of length, about 18 inches.” (Gingrich) Eighteen inches cover the length of your forearm to the tip of your middle finger. (Hagner) That is one cubit. The word, “stature” (NKJV) is from the Greek, helikia, which can mean either “age, time of life” or “bodily stature.” (Gingrich) Thus, the NASB is the more literal translation.
Jewish thought compares the length of a body part to the length of life. Psalm 39:5 reads, “Behold, you have made my days a few handbreadths.” The Psalmist compares the length of our life by a picture of our hand. The Psalmist said that his life span is only a few handbreadths. Lift up your hand. Your days are a few fingers in your hand. Thus, I think Jesus used the cubit as a measurement of one’s life span.
Jesus said that you cannot add eighteen inches to the length of your life by worrying. So do not be anxious over your food, because you cannot add an inch to your life. It accomplishes nothing.