Surrender is an action non-action. It is a refraining from action. It is a not picking up of the mind. It is a refraining, hands up, a backing away.
It cannot be defined what it is. it is not a doing. It is not a refraining from action. It is not a not picking up of the mind. These all would suggest that there is a someone or something which chooses to do something, even if that doing is a not doing. Yet there is a choice, but there is not a choice. The choice consists in knowledge, but knowledge is not a choice, not a doing.
There is a choice from one side, and that choice leads to another side, a side where there are no sides.
Sri Ramana Maharshi spoke of the idea that the ego even of knowers rose up (jnanis), but that it was blunt, broken, burned up, harmless, because the jnani’s attention was fixed so solidly on the Self or source of thoughts, of mind. Yet is the attention indeed fixed? What does it mean for attention to be fixed on the Self, which is not a something, not an object, not a dimension of attention? It might be said to be withdrawn from the objects of the mind and world, but who is so withdrawn? Would not that “it” also be an object?
It could be claimed that the Self in this case is actually the pure intellect, the subtle sattva (the reflective quality of awareness), but as Ramana Maharshi also said, such a pure intellect is effectively the pure, absolute Self, like two mirrors reflecting each other. These kinds of verbal formulations are concessions to the language of ignorance, which must conceive even the absolute in its limited, dualistic terms.