What about the sign of Jonah? Was the prophet in the great fish's belly for a complete 72 hours? The marginal note in Bullinger's Companion Bible for Jonah 1:17 reads: "Three days and three nights. The Hebrew idiom 'three days' can be used for parts of three days (and even of years): but not when the word 'nights' is added" (our emphasis). By the addition of "nights," the expression becomes more specific, precluding the idea of "parts" of days!