The superior man acts before he speaks, and afterwards speaks according to his action.

Speaking first commits you to a version of events that has not happened yet, and the gap between the announcement and the delivery is where credibility gets spent. Acting first reverses the order, so that by the time you say anything the evidence already stands behind it. It also protects you from the peculiar way that declaring an intention drains some of the motivation to carry it out.

Take the thing you have been telling people you will do. Do a piece of it before mentioning it again, and let the report follow the work rather than precede it.