In In the Midst of Alarms (1894) by Robert Barr, the author is describing a journalist at the Argus newspaper, who used to read the opposition sheets in a feverish way, saying:
He had feared that he would find life deadly dull so far from New York, without even the consolation of a morning-paper, the feverish reading of which had become a sort of vice with him, like smoking. He had imagined that he could not exist without his morning paper, but he now realized that it was not nearly so important a factor in life as he had supposed; yet he sighed when he thought of it, and wished he had one with him of current date. He could now, for the first time in many years, read a paper without that vague fear which always possessed him when he took up an opposition sheet, still damp from the press. Before he could enjoy it his habit was to scan it over rapidly to see if it contained any item of news which he himself had missed the previous day. The impending “scoop” hangs over the head of the newspaper man like the sword so often quoted. Great as the joy of beating the opposition press is, it never takes the poignancy of the sting away from a beating received. If a terrible disaster took place, and another paper gave fuller particulars than the Argus did, Yates found himself almost wishing the accident had not occurred, although he recognized such a wish as decidedly unprofessional.
What's meant by this bolded phrase, and does "so often quoted" mean "in many of times in which the word "scoop" is mentioned"?!