Is He a Messenger?

What criteria are there for establishing a man's credentials as a messenger? In S 3:183 we are told of an encounter with some Jews.

Those who said: Allah has recognised from us that we should not believe a messenger until he brings us a qurban which the fire consumes. Say: Messengers came before me with the proofs and with what you speak. So why did you kill them if you are truthful?

The Jews say that they had an understanding with Allah that they don't accept anyone calling himself a messenger until he offers a sacrifice which is consumed by fire from heaven. The author accepts what they say. But where was the sacrifice? The incident may or may not be true but if true, was this just another test for the false prophet? In 1 Kings 18 we read:

16So Obadiah went to meet Ahab, and told him: and Ahab went to meet Elijah.

17And it came to pass, when Ahab saw Elijah, that Ahab said unto him, Art thou he that troubleth Israel? 18And he answered, I have not troubled Israel; but thou, and thy father's house, in that ye have forsaken the commandments of the LORD, and thou hast followed Baalim. 19Now therefore send, and gather to me all Israel unto mount Carmel, and the prophets of Baal four hundred and fifty, and the prophets of the groves four hundred, which eat at Jezebel's table.

20So Ahab sent unto all the children of Israel, and gathered the prophets together unto mount Carmel. 21And Elijah came unto all the people, and said, How long halt ye between two opinions? if the LORD be God, follow him: but if Baal, then follow him. And the people answered him not a word. 22Then said Elijah unto the people, I, even I only, remain a prophet of the LORD; but Baal's prophets are four hundred and fifty men. 23Let them therefore give us two bullocks; and let them choose one bullock for themselves, and cut it in pieces, and lay it on wood, and put no fire under: and I will dress the other bullock, and lay it on wood, and put no fire under: 24And call ye on the name of your gods, and I will call on the name of the LORD: and the God that answereth by fire, let him be God. And all the people answered and said, It is well spoken.

25And Elijah said unto the prophets of Baal, Choose you one bullock for yourselves, and dress it first; for ye are many; and call on the name of your gods, but put no fire under. 26And they took the bullock which was given them, and they dressed it, and called on the name of Baal from morning even until noon, saying, O Baal, hear us. But there was no voice, nor any that answered. And they leaped upon the altar which was made. 27And it came to pass at noon, that Elijah mocked them, and said, Cry aloud: for he is a god; either he is talking, or he is pursuing, or he is in a journey, or peradventure he sleepeth, and must be awaked. 28And they cried aloud, and cut themselves after their manner with knives and lancets, till the blood gushed out upon them. 29And it came to pass, when midday was past, and they prophesied until the time of the offering of the evening sacrifice, that there was neither voice, nor any to answer, nor any that regarded.

30And Elijah said unto all the people, Come near unto me. And all the people came near unto him. And he repaired the altar of the LORD that was broken down. 31And Elijah took twelve stones, according to the number of the tribes of the sons of Jacob, unto whom the word of the LORD came, saying, Israel shall be thy name: 32And with the stones he built an altar in the name of the LORD: and he made a trench about the altar, as great as would contain two measures of seed. 33And he put the wood in order, and cut the bullock in pieces, and laid him on the wood, and said, Fill four barrels with water, and pour it on the burnt sacrifice, and on the wood. 34And he said, Do it the second time. And they did it the second time. And he said, Do it the third time. And they did it the third time. 35And the water ran round about the altar; and he filled the trench also with water.

Elijah's Prayer

36And it came to pass at the time of the offering of the evening sacrifice, that Elijah the prophet came near, and said, LORD God of Abraham, Isaac, and of Israel, let it be known this day that thou art God in Israel, and that I am thy servant, and that I have done all these things at thy word. 37Hear me, O LORD, hear me, that this people may know that thou art the LORD God, and that thou hast turned their heart back again. 38Then the fire of the LORD fell, and consumed the burnt sacrifice, and the wood, and the stones, and the dust, and licked up the water that was in the trench. 39And when all the people saw it, they fell on their faces: and they said, The LORD, he is the God; the LORD, he is the God. 40And Elijah said unto them, Take the prophets of Baal; let not one of them escape. And they took them: and Elijah brought them down to the brook Kishon, and slew them there. 1 Kings 18 KJV

Qur'an Contradiction: Did the Jews kill prophets who brought a sacrifice devoured by fire?

He goes on a rant accusing them of having killed messengers.

Qur'an Contradiction: Which Prophets Did the Jews Kill?

In hadith he effectively denies being a messenger by erasing his self-assumed title.

Narrated Al-Bara:

When the Prophet (ﷺ) intended to perform the `Umra he sent a person to the people of Mecca asking their permission to enter Mecca. They stipulated that he would not stay for more than three days and would not enter it except with sheathed arms and would not preach (Islam) to any of them. So `Ali bin Abi- Talib started writing the treaty between them. He wrote, "This is what Muhammad, Apostle of Allah has agreed to." The (Meccans) said, "If we knew that you (Muhammad) are the Messenger of Allah, then we would not have prevented you and would have followed you. But write, 'This is what Muhammad bin `Abdullah has agreed to..' " On that Allah's Messenger (ﷺ) said, "By Allah, I am Muhammad bin `Abdullah, and, by Allah, I am Apostle of 'Allah." Allah's Messenger (ﷺ) used not to write; so he asked `Ali to erase the expression of Apostle of Allah. On that `Ali said, "By Allah I will never erase it." Allah's Apostle said (to `Ali), "Let me see the paper." When `Ali showed him the paper, the Prophet (ﷺ) erased the expression with his own hand. When Allah's Messenger (ﷺ) had entered Mecca and three days had elapsed, the Meccans came to `Ali and said, "Let your friend (i.e. the Prophet) quit Mecca." `Ali informed Allah's Messenger (ﷺ) about it and Allah's Messenger (ﷺ) said, "Yes," and then he departed. https://sunnah.com/bukhari/58/26

Further reading: Proofs?