If you ever encounter "counter-missionaries" who attempt to challenge you with the idea that “neither Torah nor Tanach contain scriptures that tell us G-d will send a Messiah,” here's what you can respond with:
First - I know that, no matter WHAT, "counter-missionaries" WILL reject and even debunk whatever you say, because their blind minds are made up.
What I always tell people is - while there are no specific scriptures that talk about YHWH sending a Messiah, there are ALSO no specific scriptures that discuss the words "homosexuality", "gambling" or "abortion" - because those words didn't exist back then. (There also is not specific command for or about socks, either - yet we ALL wear them!)
HOWEVER, when Scripture is read IN CONTEXT, we CAN see that YHWH hates homosexual acts because homosexuals can't procreate - which hampers the production of His "likeness"/Image.
We CAN see that He prohibits "gambling" because the act gets people hooked on the hope of "getting rich quick" while they're squandering their hard-earned money with the odds stacked against them.
AND, we certainly CAN produce scriptures that show that YHWH considered the unborn to be "human life" because the penalties were stiff for killing or harming a pregnant woman's unborn child....
So....having said that, while there are no specific scriptures that say, "Thus saith the Lord, I will give the world a divine Messiah," He DID say:
Zechariah 6:12 "...and tell him, 'Yahweh-Tzva'ot says: "There is coming a man whose name is Tzemach [Sprout]. He will sprout up from his place and rebuild the temple of Yahweh. 13 Yes, he will rebuild the temple of Yahweh; and he will take up royal splendor, sitting and ruling from his throne." (CJB)
NOTHING says Yeshua would have to accomplish everything during his lifetime! YHWH's timeline is not necessarily OURS!
Deuteronomy 18: 15 "ADONAI will raise up for you a prophet like me from among yourselves, from your own kinsmen. You are to pay attention to him, 16 just as when you were assembled at Horev and requested ADONAI your God, 'Don't let me hear the voice of ADONAI my God any more, or let me see this great fire ever again; if I do, I will die!' 17 On that occasion ADONAI said to me, 'They are right in what they are saying. 18 I will raise up for them a prophet like you from among their kinsmen. I will put my words in his mouth, and he will tell them everything I order him. (CJB)
Yeshua Himself said He came to do HIS FATHER's will; not his own!
John 6: 35. Y'shua said to them, I am the Bread of Life. Whoever comes to me will not hunger. And whoever believes in me will not ever thirst. 36. But I have said to you that you have seen me, and you do not believe. 37. All who my Father has given to me will come, and whoever comes not to me I will cast outside! 38. For I came down from heaven, not to do my will, but to do the will of Him who sent me. 39. And this is His will, that of Him who sent me, that all that He has given to me I do not lose even one. 40. For this is the will of my Father, that all who see the Son and believe in him, will have life that is eternal. And I will raise him up on the last day. (AENT)
 As in the context of Miltha (the Word) or the "Manifestation" or the "Will of" YHWH coming down from heaven to do the Will of YHWH upon earth; his Spirit is of YHWH but his nephesh (soul) and body are human and temporal. This shows that Yeshua was NOT in charge; HIS FATHER WAS!
Soooo - having said that.....let's not forget to mention that Isaiah 53 is ALL ABOUT YHWH's Messiah, because NO ONE in history has EVER met ALL those qualifications that Yeshua met.
And for those who insist that Isaiah 53 is "all about Israel" - we must ask ourselves: Can Israel DIE for Israel? (No, but Y’shua did! See Matthew 27.) Can Israel be wounded for our transgressions? (No, but Y’shua was! See Matthew 27.)
Can people take Israel's garments and divide them? (No, but that certainly happened in Y’shua’s case! See John 19:23.) WHEN was "Israel" wounded for our transgressions or crushed because of our iniquities? Has the world been HEALED by "Israel"? Not hardly! Y'shua has filled myriads of Tanach prophecies - and people can reject it all they want, but they cannot CHANGE those facts!