When. It has no fixed hour, which is why it works as a standing request — after a prayer, at the start of a working day, whenever the vague wish to have one's life go well needs a form. Its four words are the form.
The words. Al-huda is guidance as a road shown and walked, not information received; the Arabic keeps the sense of being led along something. At-tuqa is from wiqaya, a shield or barrier — piety in Arabic is protective architecture rather than timidity, something a person builds between himself and harm. Al-'afaf is restraint from what is not yours: the appetite held back, but also the hand and the eye. Al-ghina is not wealth. It is sufficiency, the state of not needing, and the same word is used of the rich only because they happen to be in that state.
The last two belong together. 'Afaf is not wanting what other people have; ghina is not needing it. Ask for either alone and you get half a condition — a person who wants and abstains, or a person who has enough and still eyes the neighbour. Together they describe someone whose peace does not depend on what arrives.
Why guidance comes first. The order is not decorative. Guidance sets the direction; piety guards the road; restraint and sufficiency are what make walking it bearable. Reverse the list and you are asking for comfort and hoping direction follows.
What it does not ask for. No sum, no position, no named outcome. Every one of the four is a state of the person rather than a change in his circumstances, and a supplication built that way cannot be answered by a windfall alone.