Daniel retired from his position as one of the king’s advisers in the first year of Cyrus (1:20, 21), but God still wanted him to act like a prophet here in the third year of Cyrus (10:1). The reason he had to say the thing is true is that he was writing this years later and the thing hadn’t happened yet, and wouldn’t for a while because “the time appointed is long.”
Daniel was probably “mourning” (10:2, 3) because in the third year of Cyrus, work was stopped on the temple (Ezra 1:1-3 cf. 4:23, 24). But if the Jews were released from captivity, why was Daniel hanging around a Babylonian river (v. 4)? Well, when God told him he’d stand in his tribe’s “lot” (12:13) after he rested in death and God raised him from the dead, he took that to mean he shouldn’t go home and stand in his lot now. He should stay and minister to the many other Jews who’d gotten too comfy in Babylon to return to Israel. They might have been unfaithful, but God was no longer mad at them now that they’d served their 70 year sentence.
Daniel 10:5, 6 shows a vision of Christ in Tribulation judgment (cf. Rev. 1:9-18). The men with him didn’t see the vision but were probably frightened by the same light that frightened the men who were with Saul, who didn’t see his vision (Acts 22:7-9).
Daniel’s “comeliness” (v. 8) was his handsomeness, and the most comely thing about him was his holiness. But one look of the Lord in judgment convinced him that his holiness was corrupt, and he deserved to be judged like anyone else.
We think the angel of Daniel 10:9-12 is Gabriel, since he spoke to Daniel earlier. He came “for” Daniel’s words, i.e., on account of them. Daniel had been praying and chastening himself (v. 12) with fasting (v. 3), so God sent Gabriel to answer his prayer. But the prince of Persia held him up 21 days. That had to be a fallen angelic prince, since no earthly prince could withstand an angel for 21 seconds!
He’s called the prince of Persia because there’s a Persia in heaven, as there is a Jerusalem in heaven (Gal. 4:26; Heb. 12:22). God divided the world into 12 sections (Deut. 32:8) in Genesis 11:8, 9. Those sections were obviously named after similarly named sections in heaven. Greece had a prince too (Dan. 10:20), as did Israel (v. 21). All 24 princes are represented in heaven (Rev. 4:1-4). Earth’s rulers are corrupt, and so are most of heaven’s (Eph. 6:12, 13). The prince of Persia “withstood” an angel delivering a message from God to His people, and today we are to “withstand” (Eph. 6:13) fallen angels who try to keep God’s grace message from His people by withstanding us with “doctrines of devils” (I Tim. 4:1) that they inspire pastors to teach.
Gabriel had come to tell Daniel about the “last days” (Dan. 10:13), i.e., the last days of Israel in the Tribulation (Deut. 4:30, 31). The vision made him “dumb” (Dan. 10:15), but an angel restored his speech (v. 16, 17). Daniel calls him “my lord” out of respect (cf. Zech. 4:4), not because it was the Lord Jesus. The angel “strengthened” Daniel (Dan. 10:18) by telling him how loved he was (v. 19) and that he had nothing to “fear” because he had come in “peace” (v. 19).
If you’re looking for spiritual strength, read Paul’s epistles to learn how loved you are in Christ (Eph. 1:7) and how you have nothing to fear because you have “peace with God” (Rom. 5:1) “through the blood of His cross” (Col. 1:20). But be sure to use the strength you get from knowing these things to do what Daniel did and ask to be taught the Word (v. 19).
God didn’t strengthen David (Ps. 138:3) in some miraculous way that you don’t have access to. He did it with His Word (v. 2). That angel in Gethsemane didn’t strengthen the Lord in some miraculous way that a man who was God in the flesh didn’t have access to (Lu. 22:43). He did it by quoting Scripture to Him! And you can strengthen yourself and others too in the same way, if you learn the Word well enough to do it.
When Gabriel tells Daniel that he’s about to tell him what it says in the Scriptures (v. 21), and then tells him what it says in the Scriptures in Chapter 11, how did he do that if Daniel hadn’t written Chapter 11 yet? This is an indication that God wrote the Bible before the creation of the world and then later spoke it through men.