Muhammad's (pbuh) name appeared in Haggai 2:7 under the Hebrew word mahmad, which means praised one (Muhammad is Arabic for praised one). It almost undoubtedly is referring to the Arabic Prophet Muhammad.

The 5th chapter of Songs of Solomon is discussing someone. Jews will say it is discussing Solomon, while Christians will say it is discussing Jesus. Considering this is the Songs of Solomon, it would seem logical that it is discussing Solomon. The verses describing this mystery man have the narrators speech conjugated in the feminine (meaning it is a woman who is describing this man) so it is possible that it is one of Solomon's wives discussing her Husband (Solomon). However, if a Christian tries to assert that Jesus is being discussed, then they are insinuating that this is discussing a future prophet (a man who was not yet alive at that point), a prophesy. If the 5th chapter of Songs of Solomon is looking into the future, then there is no doubt it is discussing the Prophet Muhammad (pbuh)

In other words, if Songs of Solomon chapter 5 is discussing a man to come after that time, it is without a doubt the Prophet Muhammad (pbuh), as it even mentions his name. Any Christian who believes Jesus is the Messiah, and believes that books were sent down by God after the TaNaKh (Jewish Bible), then surely they should take into account what they read.