20. as when one doth hunt a partridge—People in the East, in hunting the partridge and other game birds, pursue them, till observing them becoming languid and fatigued after they have been put up two or three times, they rush upon the birds stealthily and knock them down with bludgeons [SHAW, Travels]. It was exactly in this manner that Saul was pursuing David. He drove him from time to time from his hiding-place, hoping to render him weary of his life, or obtain an opportunity of accomplishing his destruction.

     52-54. a bird—which is destitute of counsel and strength. The allusion seems to be to Pr 1:17 [CALVIN].