"Belay on?" Any wise climber asks that question before he or she grips rocks and locates toeholds. A belayer is a climber's best friend - an actual lifeline holder.
My youngest son recently joined a rock gym climbing club. Before doing so, he and I went to the gym where he climbed while I belayed. As he ascended the wall higher and higher, I provided more rope. When he was ready to descend, I monitored his return to the ground. I never let go of the rope.
Any belayer worth his or her salt always keeps a solid grip.
Climbers trust their belayers and really don't need to ask, "Belay on?" Yet they do because the response to the affirmative "Belay on!" provides rock-solid (pun intended) comfort.
For me, the Word of God (Bible) is my "Belay on!" from God. He assures me of what I have trusted for over 30 years - His love. I don't really need to ask, "Belay on?" (as in, "God, have You got this? Are You here for me?"). His word assures me over and over that He is in control. He says loudly and clearly, "Belay on!"