Matthew 12:40

“For as Jonas was three days and three nights in the whale’s belly, etc.] Or “in the belly of a great fish”, as is said, (Jon 1:17) for that it was a whale, is not there said, nor is it certain it was; nor from the smallness of its swallow, is it thought probable it should; nor does the word here used, necessarily imply one, but some large fish; nor are there whales in the Phoenician Sea: it might be a kind of a sea dog, called Carcharias, and sometimes Lamia, or Lamina, from its vast swallow; in which whole men; even in coats of mail, have been found. However, be it what it will, Jonas was three days and three nights in the belly of it; which agrees with the account in the above mentioned…”

“For as Jonas was--"a sign unto the Ninevites, so shall also the Son of man be to this generation" (Luk 11:30). For as Jonas was three days and three nights in the whale's belly-- (Jon 1:17). so shall the Son of man be three days and three nights in the heart of the earth--This was the second public announcement of His resurrection three days after His death. (For the first, see Joh 2:19). Jonah's case was analogous to this, as being a signal judgment of God; reversed in three days; and followed by a glorious mission to the Gentiles. The expression "in the heart of the earth," suggested by the expression of Jonah with respect to the sea (Jon 2:3, in the Septuagint), means simply the grave,…”

“We would see a sign from thee - See Luke 11:16, Luke 11:29-32. A “sign” commonly signifies a miracle - that is, a sign that God was with the person or had sent him. Compare the notes at Isaiah 7:11. Luke adds that this was done “tempting him;” that is, trying him, doubting if he had the power to do it. If these persons had been present with him for any considerable time, they had already seen sufficient proofs that he was what he claimed to be. They might have been, however, those who had recently come, and then the emphasis must be laid on “we” - we, as well as the others, would see a proof that thou art the Christ. In either case it was a temptation. If they had not seen him work a…”

“Three days and three nights - It was customary with the eastern nations to reckon any part of a natural day of twenty - four hours, for the whole day. Accordingly they used to say a thing was done after three or seven days, if it was done on the third or seventh day, from that which was last mentioned. Instances of this may be seen, Kg1 20:29; and in many other places. And as the Hebrews had no word to express a natural day, they used night and day, or day and night for it. So that to say a thing happened after three days and three nights, was with them the very same, as to say, it happened after three days, or on the third day. See Est 4:16; Est 5:1; Gen 7:4, Gen 7:12; Exo 24:18; Exo 34:28.…”

“as: Jon 1:17 so: Mat 16:21, Mat 17:23, Mat 27:40, Mat 27:63, Mat 27:64; Joh 2:19 in the heart: Psa 63:9; Jon 2:2-6 Matthew 12:41”