Nine in the fourth place is the most powerful line in Enthusiasm and a querent who draws it is usually the person the situation actually runs on: the one whose energy sets the pace, whose absence would stop the work, whose commitment other people are matching. The reading promises great success and gathering support, and it makes both contingent on a single interior discipline rather than on any action.
That discipline is the refusal of suspicion. The classical text is specific, and the specificity is what makes the line useful. Someone in this position will eventually wonder whether the people around them are loyal to them or to what they provide, and whether a colleague's enthusiasm would survive a lean season. The line treats that wondering as the one thing capable of undoing the position, because a gathering held together by trust dissolves the moment the centre begins auditing it.
Practically, a reading landing here counsels against hedging: no quiet second options, no information withheld from the people carrying the work, no testing of anyone's commitment. The querent is also being warned against the opposite temptation, which is to convert their central role into formal authority. The strength of this position is that it energises rather than commands, and the friends who gather are gathering freely. Both the success and the support last exactly as long as that stays true.