Jonah 1:
Gill:
Elsewhere in Mark, Jesus talked about "after three days", Mark 8:
Acts 10:
See also Three days and nights.
The Hebrew "three days and three nights" does not mean 3 24-hour days. It was a figure of speech.17 And the Lord appointed a great fish to swallow up Jonah. And Jonah was in the belly of the fish three days and three nights.
Gill:
Similarly, Pulpit:and Jonah was in the belly of the fish three days and three nights: that is, one whole natural day, consisting of twenty four hours, and part of two others.
Keil and Delitzsch:Three days and three nights; i.e., according to Hebrew usage, parts of the days and nights; i.e. one whole day, and parts of the day before and after this.
Benson:The three days and three nights are not to be regarded as fully three times twenty hours, but are to be interpreted according to Hebrew usage, as signifying that Jonah was vomited up again on the third day after he had been swallowed
Jesus cited Jonah in Matthew 12:“The Hebrew language,” says Lowth, “has no one word to express what we call a natural day; so that what the Greeks express by Νυχθημερον, they denote by a day and a night. Therefore the space of time consisting of one whole revolution of twenty-four hours, and a part of two others, is fitly expressed in that language by three days and three nights. Such a space of time our Lord lay in the grave;” (that is, one whole νυχθημερον, or natural day, and part of two others;) “and we may from thence conclude that Jonah, who was an eminent figure of him in this particular, was no longer in the fish’s belly.”
That was the only place in the NT where Jesus mentioned three days and three nights and it was in connection with Jonah.40 For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth.
Elsewhere in Mark, Jesus talked about "after three days", Mark 8:
Mark 9:31 And he began to teach them that the Son of Man must suffer many things and be rejected by the elders and the chief priests and the scribes and be killed, and after three days rise again.
Mark 10:31 For he was teaching his disciples, saying to them, “The Son of Man is going to be delivered into the hands of men, and they will kill him. And when he is killed, after three days he will rise.”
Other listeners understood that as "in three days", Mark 14:34 And they will mock him and spit on him, and flog him and kill him. And after three days he will rise.
More precisely, Jesus frequently talked about "on the third day", Luke 9:58 “We heard him say, ‘I will destroy this temple that is made with hands, and in three days I will build another, not made with hands.’”
Luke 24:22 Saying, “The Son of Man must suffer many things and be rejected by the elders and chief priests and scribes, and be killed, and on the third day be raised.”
Matthew 16:7 That the Son of Man must be delivered into the hands of sinful men and be crucified and on the third day rise.” 46 And said to them, “Thus it is written, that the Christ should suffer and *on the third day rise from the dead,
Matthew 17:21 From that time Jesus began to show his disciples that he must go to Jerusalem and suffer many things from the elders and chief priests and scribes, and be killed, and on the third day be raised.
Matthew 20:23 And they will kill him, and he will be raised on the third day.” And they were greatly distressed.
That's what the Jews understood, Matthew 27:19 And deliver him over to the Gentiles to be mocked and flogged and crucified, and he will be raised on the third day.”
In fact, on the day of resurrection, Jesus met two disciples on the road to Emmaus, Luke 24:63 And said, “Sir, we remember how that impostor said, while he was still alive, ‘After three days I will rise.’ 64 Therefore order the tomb to be made secure until the third day, lest his disciples go and steal him away and tell the people, ‘He has risen from the dead,’ and the last fraud will be worse than the first.”
That confirmed that Jesus rose on the 3rd day. There are other confirmations,21 But we had hoped that he was the one to redeem Israel. Yes, and besides all this, it is now the third day since these things happened.
Acts 10:
1 Corinthians 15:40 But God raised him on the third day and made him to appear,
"3 days and 3 nights" was a figure of speech; in fact and precision, Jesus rose on the 3rd day after only 2 nights.4 that he was buried, that he was raised on the third day according to the Scriptures,
See also Three days and nights.