The usage in the sense of "to be exacting" in Jewish texts is Mishnaic. DJBA may be correct in connecting it directly with dwq "to observe (carefully?)" rather than dqq "to crush" from the perspective of JBA, but given the antiquity of the related form dqdq "small" (an elative of dq "thin"), we suspect that the semantic relationship proposed by DJBA actually goes the other way, i.e., that both verbs dwq and dqdq are ultimately and separately derived from dq, whose root, of course, is dqq.