Threading the needle takes two hands. One holds the needle steady, the other pinches the thread just behind its leading edge and guides the point through the eye of the needle.
Two hands work side by side. One pushes the thread, whilst the other transfers the needle to other threading thumb and finger, and takes hold of thread from the right. Together they work as one to simplify what might be an impossible task alone. The one hand assists the other and subjects itself to the intent of the other. The success comes when the needle is threaded for work. The left hand now steadies the work piece so that the right sews unhindered. Both are equally valued to completing the task, but the needle pushed decides more than the left, and greater demand is placed on the right for accuracy. Even so, greater subjection comes to the left as one hand in subjection to the right and then also to the right which must determine accuracy in the work.
So it is when two people share a life in work together. One serves the other with their gift whatever the gift may be. The head coordinates both hand and eye to coordinate every operation. Each senses the need of the other and turns the eye of the needle or the thread to unite the two. Neither seeks to dominate even though one may take the lead. Both have equal importance though neither strives for it.