He is the Truthful, the Trustworthy
Prophet Muhammad, Peace Be upon Him, was called the Trustworthy among His people. They knew very well that He did not lie, He was indeed a Prophet and the Message that He was calling for is true, yet they denied and refused Islam. Abu Jahl used to say to the Prophet: “We do not call you a liar, you are indeed truthful for us, but we deny what you have brought.” 
Foretelling of the coming of Prophet Muhammad in the Bible
Signs in the Old Testament and the New Testament
Almighty Allah paved the way for the coming of Prophet Muhammad, the Seal of Prophets. Allah confirmed the coming of Prophet Muhammad in the Old and New Testament. Allah mentioned Prophet Muhammad, Peace Be upon Him, in the Torah more than once, He mentioned His name, description and tribe, such as:
1- In the Book of Genesis 49:10, Jacob tells his sons: “The scepter will not depart from Judah, nor the ruler's staff from between his feet, until he comes to whom it belongs and the obedience of the nations is his.” History knows no Prophet that dominated the earth and nations submitted to him after Judah except Prophet Muhammad, Peace Be upon Him.
As for the description of Messenger Muhammad, Peace Be upon Him, in the Torah, it is narrated by Imam Bukhari with a sound chain of transmission from Abdullah ibn Amr ibn al-Ass that the verse no. 45 in the Qur’an which describes Prophet Muhammad in Surat al-Ahzab: “O Prophet, indeed We have sent you as a witness and a bringer of good tidings and a Warner.” has a counterpart in the torah. In the torah Prophet Muhammad is described as: “O Prophet, indeed We have sent you as a witness and a bringer of good tidings and a Warner, and also as a sanctuary for the gentiles. You are My servant and My messenger; I have called you al-Mutawakkil (the dependant on Allah). He is not rude or harsh, nor is he noisy in the marketplaces. He does not compensate a bad deed with another; rather, he pardons and forgives. Allah will not cause him to die until he has amended the altered religion through him with their saying, 'La ilaha ill-Allah.' Blind eyes, deaf ears and closed hearts will be opened by him.”
2- In the Standard Revised Version of the Old Testament published by the British Bible Society, there is a text of the words addressed by the Lord to Moses, Peace Be upon Him: “I will raise up for them a prophet like you from among their brethren, and I will put my words in his mouth. He will tell them everything I command him.” (Deuteronomy 18: 18)… In this prophecy, there is an indication that this matter will be transferred from the Israelites to Arabs, because if the foretold Prophet was from the Israelites the statement would have been: “I will raise up for them a prophet like you from themselves,” i.e. from the Israelites, but it was stated as “from among their brethren” which means, from among their fellow brothers, i.e. the Arabs, because Prophet Ishmael is the father of Arabs, He is the brother of Prophet Isaac, the father of the Israelites. We have never heard of a Prophet that was sent down and assigned with the Message by Almighty Allah among their Arab brothers except Prophet Muhammad, Peace Be upon Him.
3- In the same Book, the foretold Prophet who will come with the blessed divine laws is mentioned once again: “And he said, The LORD came from Sinai, and rose up from Seir unto them; he shined forth from mount Paran… he came with ten thousands of saints, from his right hand went a fiery law for them.” (Deuteronomy 33: 2) .. Three great places of the revelation are mentioned; Sinai where Prophet Moses received the revelation, Seir where Prophet Jesus received the revelation, and Paran (Mecca and the land of Hejaz) inhibited by Prophet Ishmael, Peace Be upon the three of them. The Old Testament defined Paran as Mecca, it was mentioned in another context about Prophet Ishmael: “God was with the boy as he grew up. He lived in the desert and became an archer. While he was living in the Desert of Paran, his mother got a wife for him from Egypt.” (Genesis: 21/20-21)
If the Torah referred to a Prophethood that will be sent down on Mount Paran, it would mean that it was going to be given to Prophet Ishmael’s descendents, because they are the inhabitants of Paran. The ten thousands of saints are the companions of Prophet Muhammad, Peace Be upon Him, which was their number when they entered Mecca. Otherwise, who is the Prophet that received the revelation on the Mount Paran (Mecca), and came back with ten thousand followers opening the city of Mecca?
In the Book of Habkkuk: “I see God moving across the deserts from Edom, the Holy One coming from Mount Paran. His brilliant splendor fills the heavens, and the earth is filled with his praise.” (Habkkuk: 3/3)… This is another reference to Mecca.
As for the New Testament, we can find a lot of prophecies and reference to Prophet Muhammad. Prophet Jesus, Peace Be upon Him, foretold the coming of Prophet Muhammad, Peace Be upon Him, many times because there was no other Prophet between the two of them. This is why there are a lot of references to Prophet Muhammad, even in the altered bibles where there are both sound and forged texts. Some of these references to Prophet Muhammad are as mentioned:
1- Jesus says: “very truly I tell you, it is for your good that I am going away. Unless I go away, the Advocate will not come to you; but if I go, I will send him to you.” (John: 16/7)
ProphetJesus, Peace Be upon Him, said about this Advocate: “He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come.” (John: 16/130… This is how Almighty Allah describes Prophet Muhammad in the Qur’an: “Nor does he speak from [his own] inclination. It is not but a revelation revealed.” (Surat An-Najm: 3-4)
3- In the Gospel of John, Jesus says: “And I will ask the Father, and he will give you another Periqlytos to help you and be with you forever.” (John: 14/16) … Periqlytos literally means Ahmad, which confirms what Allah says in the Qur’an: “And [mention] when Jesus, the son of Mary, said, "O children of Israel, indeed I am the messenger of Allah to you confirming what came before me of the Torah and bringing good tidings of a messenger to come after me, whose name is Ahmad." (As-Saf: 6)
4- In the Gospel of Matthew Jesus says: “And if you are willing to accept it, he is the Elijah who was to come. Whoever has ears, let them hear.” (Matthew: 11/14)… The Abjad numerals of the name Elijah is exactly the same as the Abjad numerals of the name Ahmad.
Muhammad Ali al-Sabony, Safwat al-Tafasir, Cairo, Dar al-Sabony, First Part, Page 386, Quoting Al-Bahr Al-Muhit 4/112
Ali Jummah, Muhammad, Peace Be upon Him, the Messenger of Allah to the Worlds, Page 74-83.