In Ruth 1:1, there is a Masoretic note on שְׁפֹט which I do not understand:
The picture is a little unclear, but the note says (I have highlighted the letters with a dot above them):
ב חד מל וחד חס
I read this as:
Twice, once spelled plene and once spelled defectively
However, I don't understand how this applies to this word. The form (a qal infinitive construct of שׁפט) occurs more than twice (13 times, if my count is correct: Ex. 18:13; 1 Sam. 8:5, 6; 1 Kgs. 3:9 [2x]; Joel 4:12; Ob. 1:21; Ps. 10:18; 51:6; 96:13; 98:9; Ruth 1:1; 1 Chr. 16:33).
(If the form is interpreted as a qal infinitive absolute I can understand (this form occurs only once elsewhere and is spelled plene there: Gn. 19:9). But I really don't see how this form could be read as an infinitive absolute. Also I would expect a reference to Gn. 19:9 in that case.)
How should I interpret this note?