The qualities of mind we’re developing are like strategic weapons. We develop mindfulness. We develop alertness. We pick out our one object of meditation — “This is what I’m going to fasten on” — and then we both keep it in mind and stay aware of it. When we refuse to let go of it, when we hold on tight to a single object, it becomes the quality called singleness of preoccupation. When this singleness of mind arises, it can cut through restlessness, cut through anxiety. It includes both mindfulness and persistence, and can keep the mind firmly gathered in one place.
(Ajahn Suwat)