For the Activity of My Limbs

Everytime that I would go to testimony service, at church, one of the Older Saints would get up and Thank God "for life, health and strength and for the activity of my limbs." These were not terms that were used in my house. They were foreign to me and so many people would say it, over and over again. I felt like I understood the first half, "life, health and strength" ;but, why the activity of my limbs and in just that way everytime. This wasn't Biblical language, like most of the other enigmatic phrases that the Saints would use to express gratitude and joy. My natural expressions of joy were "Wowee and Far out!" but you can't say that at church testimony service. So I had to find out what it meant, to Thank God for the Activity of my limbs a beautiful statement. Technically, I knew what each of the words meant, but not until now when my knee is frequently and unexpectingly achy enough to make me wonder if it will hold me up do I understand somewhat why, in just that tone of voice, the Godly ones would rise and give God thanks for "The activity of my limbs!"
I said, Ezra, shake your philanges, that is "the activity of your limbs". cleaning up for Aunt Jackie coming over today, that is the activity of your limbs. "Having done all to stand"...and thank God for the activity of MY limbs!