13. I can do all things--Greek, "I have strength for all things"; not merely "how to be abased and how to abound." After special instances he declares his universal power--how triumphantly, yet how humbly! [MEYER].
      through Christ which strengtheneth me--The oldest manuscripts omit "Christ"; then translate, "In Him who giveth me power," that is, by virtue of my living union and identification with Him, who is my strength (Ga 2:20). Compare 1Ti 1:12, whence probably, "Christ" was inserted here by transcribers.

JFB.