“Look!” The Greek word is idou (#2400 ἰδού), and it is used to get our attention. See commentary on Matthew 1:20 (“Look!).
“What do you want with us?” The literal Greek is, “What is there to us and to you?” This was originally a Semitic idiom, but it was pulled into the Greek idiomatic language. As with many idioms, its meaning is somewhat flexible, depending on the context in which it is used. Here, the essence of the message is “Leave me alone” (Lenski). Mark Strauss writes, “The question ‘what do you want with us’ comes from a Hebrew idiom. It is a response to (perceived) inappropriate intervention and can mean ‘What do you have against me?” or ‘Why are you trying to involve me?’ (cf. Judg. 11:12; 2 Sam. 16:10; 19:22; 1 Kings 17:18; 2 Kings 3:13; 2 Chron. 35:21; cf. Matt. 8:29; Mark 5:7; Luke 8:28; John 2:4) Here the question is rhetorical: ‘Mind your own business!’ or ‘Get out of my face!’” (Exegetical Commentary on the New Testament; commentary on Mark 1:24). However, the phrase is also used when Jesus was speaking to his mother about changing water to wine, and there the essence is more, “What is that to me and to you?” (see commentary on John 2:4). This phrase is spoken by demons 5 times in the Four Gospels, but two are in the singular, as here, and three are in the plural. This is important and gives us a peek into how demons work. In this record in Matthew, while there are many demons in these men, Matthew has more than one speaking, while Mark and Luke are singular, as if only one demon was speaking. Thus, one is in charge, but others are chiming in. The demons are bothered by Jesus Christ and are challenging him; they are not asking him a serious question as if they cared to get an answer.
The Word of God records several incidences of demons speaking to Jesus: In the Synagogue: Mark 1:24, Luke 4:34 (τί ἡμῖν καί σοι [both plural]); from the tombs: Matthew 8:29 (τί ἡμῖν καί σοί [plural]); and Mark 5:7, Luke 8:28 (τί ἐμοὶ καὶ σοί [singular]).
The slight difference in the Greek words in the record of the tombs shows that in the record of the tombs there was one demon who was the main speaker, but also that the demons spoke as a group. The Greek word hemin (ἡμῖν) is plural, “we,” while emoi (ἐμοι) is singular, “I.”
“before the appointed time.” The word translated “appointed time” is kairos, whereas the Greek word for the flow of time is chronos. The Devil and the demons know that there is a time coming when they will be tormented in Gehenna and eventually destroyed. They understand God’s retributive justice, and they understand the meaning of the Flood, which was the destruction of the ungodly (2 Pet. 2:5); and the meaning of the destruction of Sodom and Gomorrah, which was also an example of the destruction of the ungodly (Jude 1:7). They know they will be bound, tormented, then destroyed (Dan. 7:12; Matt. 25:41; Rev. 20:10). They knew, however, that the Messiah was to have his heel bruised before he bruised the head of the Serpent (Gen. 3:15), and so they asked if he had come to torment them before the proper time. There were demons who had caused the Nephilim (Gen. 6:4) during the days of Noah that led to the hardening of the human race and its eventual destruction. Genesis 6:5 describes how great mankind’s wickedness had become in the days of Noah by saying that “every inclination of the thoughts of his heart was only evil all the time.” The demons who caused that hardening were now imprisoned in Tartarus, “gloomy dungeons,” awaiting the Judgment (1 Pet. 3:19-20; 2 Pet. 2:4). Although not the Gehenna, Tartarus must be very unpleasant, to say the least. These demons thought Jesus might send them to Tartarus too, so they asked if he had come to torment them before “the time,” i.e., their being bound in the Abyss (Rev. 20:1-3) and then eventually thrown into Gehenna (Rev. 20:10).